JP3594577B2 - Liquid crystal display device and viewfinder using the same - Google Patents

Description

【０２８４】
と表せる。最大モアレピッチが最小となるのは
【０２８５】
【数２】

【０２８６】
のときであり、ｎが大きいほどモアレの変調度が小さくなる。したがって、（数２）を満たすようにＰｒ／Ｐｄを決めればよい。ただし、フレネルレンズ５５２は同心円状の溝が形成されており、液晶表示パネル１３３３の画素はマトリックス状に配置されているから、（数２）における各ピッチＰｒ、Ｐｄの決定の仕方が多少難しい。しかし、よりモアレの発生を軽減できる値は（数２）を考慮し実験等により導きだせるであろう。
【０２８７】
なお、（数２）において、ｎは整数値である。画素ピッチＰｄは液晶表示パネル１３３３の画素サイズ等により決定されるから定数値である。したがって、フレネルレンズ５５２のピッチＰｒをフレネルレンズ５５２の作製時に考慮して最適な値に定める必要がある。ｎは整数値であるからＰｒは量子的な値となる。フレネルレンズ５５２の作製時、精度、加工上の問題から上式に合致させて、Ｐｒの値を定めることは困難である。したがって、Ｐｒの値が多少理想値から離れることになる。実用上は多少離れても問題がない。目安として±２０％以内、好ましくは±１０％以内にすればよい。
【０２８８】
フレネルレンズ５５２はアクリルもしくはポリカーボネート樹脂を加工したものである。一例として光洋（株）から発売されているものを採用することができる。フレネルレンズ５５２は少量の場合は工作機械を用いて作製することもできるが、大量に作製する場合は金型を用いて作製する方が容易であり、かつ低コスト化が図れる。フレネルレンズ５５２は平面をランプ１１側にむけているが、反射率を低下させ、これはフレネルレンズ５５２に入射する光量を大きくするためである。また、正弦条件も満足させるためである。
【０２８９】
図８３はフレネルレンズ５５２を一枚使用して集光手段を構成しているが、複数のフレネルレンズ５５２を用いて集光手段を構成してもよいことは言うまでもない。また、フレネルレンズ５５２と平凸レンズとを組み合わせて構成してもよい。また図６０の構成でもよい。図５９（ａ）はフレネルレンズ５５２ａの光入射面を凹面にした構成である。このように凹面に形成することによりレンズに入射する光の角度が相対的に小さくなり反射光は減少する。
【０２９０】
なお、本発明に関連する参考例のビューファインダの説明において液晶表示パネル１３３３に略平行光を入射させるとしたが、これに限定するものではない。たとえば、図５７の光線５１ｂの場合は液晶表示パネル１３３３に入射する主光線は斜めとなっているが、多少の斜めとなっても実用は支障がない。
【０２９１】
フレネルレンズ５５２の溝が、拡大レンズ１３３６を介してみえるため拡散板１５を液晶表示パネル１３３３とフレネルレンズ５５２間に配置する。しかし、特によくみえる（みえてしまう）のはフレネルレンズ５５２の中央部である（図９２の９２１に示す領域）。フレネルレンズ５５２の外周部はほとんどみえない。そこで、図９２（ｂ）に示すようにフレネルレンズ５５２の中央部に拡散部９２１を形成する。拡散部９２１とは具体的には拡散板１５を小さくきったもの等が該当する。その他、図３４の技術的思想を拡散板１５に適用することも有効である。
【０２９２】
なお、拡散板１５とは光学的なローパスフィルタであり、先に説明した拡散板の他、回折格子、プリズムシート、マイクロレンズアレイ、セルホックレンズアレイ等も含む概念である。さらに拡散板等のローパスフィルタを使用せず、以下に示すＭＴＦの概念を用いる方法も含む。
【０２９３】
拡散板１５は集光手段（フレネルレンズ、集光レンズ５２２）からの出射光の指向性を悪くさせ、液晶表示パネル１３３３の表示輝度を低下させる。そこで、拡散板１５を不要とする構成の一方法としてＭＴＦ（Ｍｏｄｕｒａｔｉｏｎ Ｔｒａｎｓｍｉｓｓｉｏｎ Ｆｕｎｃｔｉｏｎ）を考慮すればよい。その説明を図９４に示す。通常、拡大レンズ１３３６は液晶表示パネル１３３３の光変調層にピントがあうようにされている（光変調層の虚像が良好に見えるようにフォーカス調整がされている。あるいは観察者がフォーカス位置が合うように拡大レンズ１３３６の位置を調整する）。ここでピントがあう位置（距離）がｆとする。拡大レンズ１３３６とフレネルレンズ５５２との距離がｆであれば、フレネルレンズ５５２の溝にピントが合う。逆にいえば拡大レンズ１３３６とフレネルレンズ５５２までの距離がｆと異なるほどフレネルレンズ５５２の溝はピンボケとなり観察者からは見えなくなる。
【０２９４】
光学分野では結像（ピント）に関する比較としてＭＴＦを用いる。たとえば、少し乱暴な表現であるが、ＭＴＦが１００％では無限の解像度でピントがあっていることをいう。ＭＴＦが小さいほどピンボケであることを意味する。図９４に示すように、ＭＴＦは光学系の構成・設計により種々のものを作成できる。図９４で距離０とは拡大レンズ１３３６と液晶表示パネル１３３３の変調層までの距離がｆである（ピントがあっている）ことを意味する。そこからずれるほど解像度は劣化する。
【０２９５】
光学設計によればピントがあっている点から少しずれるとＭＴＦが急激に劣化する構成（図９４の点線）、かなりはなれてもＭＴＦが劣化しない構成（図９４の実線）が実現できる。本発明に関連する参考例のビューファインダでは、図９４の点線の構成であることが好ましい。
【０２９６】
つまり、ＭＴＦが２０％以下となる位置にフレネルレンズ５５２をおく。実線の場合ではＭＴＦが２０％以下となる点がＸ２とするとビューファインダの全長が長くなってしまう。好ましくはＭＴＦは１０％以下となる位置にフレネルレンズ５５２を配置する。
【０２９７】
以上のようにフレネルレンズ５５２をＭＴＦが低下する位置に配置すれば、フレネルレンズ５５２の溝のＭＴＦ（解像度）が低下し、溝は見えなくなるから、拡散板１５が必要でなくなる。また、フレネルレンズ５５２の溝が見えなくなるということは、溝位置を通過した光が液晶表示パネルに到達したときに周期性がなくなっているため、モアレも発生しにくくなる。
【０２９８】
一例として本発明に関連する参考例のビューファインダに用いたフレネルレンズ５５２の直径は２０ｍｍであり、焦点距離は２２ｍｍである。焦点距離ｄが短くなるほど発光素子（ランプ１１）とフレネルレンズ５５２間の距離ｄを短くできビューファインダのコンパクト化が可能となるが、フレネルレンズ５５２の光集光効率が低下する。逆にあまり焦点距離ｄが長いと光集光効率は良くなるがビューファインダの全長が長くなりすぎる。その場合は、フレネルレンズは２枚用いるべきである。さすれば焦点距離は短くできる。
【０２９９】
フレネルレンズ５５２の焦点距離ｄは液晶表示パネル１３３３の有効表示領域の対角長ｄｐに応じて決定する。焦点距離はｄｐの０．６倍以上２．０倍以下とし、さらに好ましくはｄｐの０．８倍以上１．５倍以下にする。
【０３００】
ビューファインダは、使用時は使用しやすさの点からも一定の長さ（全長）があった方がよいが、携帯時はできるだけ短いこと（コンパクトなこと）が望ましい。そこで本発明に関連する参考例は、液晶表示パネル１３３３とフレネルレンズ５５２間の距離ｄ２および、フレネルレンズ５５２とランプ１１間の距離ｄ１を収縮できるようにしている。そのため、フレネルレンズ５５２はボデー１３２１ｂに取り付けられ、ランプ１１等はボデー１３２１ｃに取り付けられている。図８４は収縮した時の構成図である。図８３のＡ、Ｂ間にバネ等（図示せず）が配置されており、図８３の伸長状態と、図８４の収縮状態とを切り換えることができる。特にフレネルレンズ５５２が平面状であるから収縮しやすい。
【０３０１】
なお、図８３ではｄ１およびｄ２の両方を収縮できるとしたが、図８１に示すように一方のみを収縮できるように構成しても携帯時のコンパクト化に寄与できることはいうまでもない。また凹レンズ１３３６ｂは収差、色補正用のレンズであり、図１の構成のビューファインダにも適用することが好ましい。また、凹レンズ１３３６ｂは凸レンズでもよい。
【０３０２】
ビューファインダは観察者の瞳の位置が接眼カバー１３３２によりほぼ固定されるため、その背後に配置する光源は指向性が狭くてもよい。光源として蛍光管を用いたライトボックス１３３１（図１３７）を用いる従来のビューファインダでは、液晶表示パネル１３３３の表示領域とほぼ同じ大きさの領域からある方向の微小立体角内に進む光だけが利用され、他の方向に進む光は利用されない。つまり、光利用効率が非常に悪い。
【０３０３】
本発明に関連する参考例では、発光体の小さな光源１１を用い、その発光体から広い立体角に放射される光をフレネルレンズ５５２等により平行に近い光に変換する。こうすると、フレネルレンズ５５２等からの出射光は指向性が狭くなる。観察者の視点が固定されておれば前述の狭い指向性の光でもビューファインダの用途に十分となる。発光体の大きさが小さければ、当然、消費電力も少ない。以上のように、本発明に関連する参考例のビューファインダは観察者が視点を固定して表示画像を見ることを利用している。
【０３０４】
図８５は図８３のビューファインダをビデオカメラ本体４３１に取りつけた構成である。ビューファインダ使用時は留め具８５１（突起）により収縮された状態でビデオカメラ本体４３１に格納される（図８５（ａ）参照）。ビューファインダ使用時は留め具８５１による固定がはずされ（図８３）に示すＡ、Ｂ部が伸長されてランプ１１により液晶表示パネル１３３３に平行光が適正に照射されるようになる。
【０３０５】
しかし、図８３のようにフレネルレンズ５５２とランプ１１間の収縮機構がないとｄ１の距離を短くできずビューファインダの全長が長くなる。その場合は図８１のようにランプ１１とフレネルレンズ５５２間にミラー７５１を配置して光路を折り曲げればよい。図８１の突き出た部分（挿入部８１１）は撮像レンズ４３２を有するビデオカメラ本体４３１に挿入するように設計あるいは構成すれば全く障害とならない（図８１（ｂ）参照）。つまり、挿入部８１１を軸として観察者が見る方向に自由に回転できるようにする（図８１（ｂ）点線を参照）。
【０３０６】
ＴＮ液晶表示パネル１３３３は光変調を行うのに偏光板１３３４が必要である。最適な表示コントラストを得るためには偏光子１３３４ａと検光子１３３４ｂとの偏光軸角度を調整する必要がある。その角度は液晶表示パネル１３３３の液晶層に印加する電圧との関係があり、個々の液晶表示パネルの特性にあわせて調整する必要がある場合が多い。図８２に示すようにつまみ８２１はフレネルレンズ５５２につながっており、つまり８２１を上下させることによりフレネルレンズ５５２が回転するとともに偏光子１３３４ａの偏光軸も回転する。したがって偏光軸を個々の液晶表示パネル１３３３の特性にあわせて容易に調整できる。
図８１の構成は前記調整を容易にした構成である。フレネルレンズ５５２に偏光子１３３４ａを貼り付けている。偏光子１３３４ａはレンズ中心を軸として回転できるように構成されている。つまり、フレネルレンズ５２２を回転させることにより偏光子１３３４ａの偏光軸も回転し、偏光子１３３４ａの偏光軸と検光子１３３４ｂの偏光軸との角度を調整できる。角度を調整することにより表示パネル１３３３の画像が最も良好に見える位置に調整をする。
【０３０７】
ランプ１１から放射された光の一部はフレネルレンズ５５２等で反射されて迷光となる。前記迷光を防止するためにはフレネルレンズ５５２等に反射防止膜を形成すればよい。しかし、反射防止膜を形成しても迷光の発生は完全に防止することはできない。
【０３０８】
迷光は表示画像のコントラストを低下させる要因となる。この問題を回避するために、図９３のようにランプ１１とフレネルレンズ５５２の間に円形絞り９３１を配置してもよい。円形絞り９３１は中央部に円形状窓を有し、複数の絞りが同心円状に所定の間隔を設けて配列されている。円形絞り９３１はランプ１１から出た光がフレネルレンズ５５２の有効領域に直接入射する光だけ通過するようにしている。また、ボデー１３２１と接眼リング１３３５の内面は、光の反射を防止するために黒色あるいは暗色としている。ランプ１１から放射される光のうち、不要な光は円形絞り９３１の遮光部で吸収され、また、吸収されずにわずかに反射する光は他の絞りの遮光部またはボデー１３２１の内面で吸収されるので、フレネルレンズ５５２に入射しない。したがって、液晶表示パネル１３３３への不要光入射による表示画像のコントラスト低下は非常に小さくなる。絞りは１枚でもよいが、枚数が多いほど効果は大きくなる。
【０３０９】
液晶表示パネル１３３３は通常ブラックマトリックス（図示せず）が形成されている。ブラックマトリックスは、液晶表示パネル１３３３の信号線上の液晶の動きを見えなくするため、または／および画素をスイッチングする薄膜トランジスタへの光を遮光するために用いる。しかし、液晶表示パネル１３３３の画素数が少ない場合は前記ブラックマトリックスが目立ち画像品位が低下してしまう。そこで、図９３に示すように、液晶表示パネル１３３３と観察者の瞳との間に、光学的ローパスフィルタとして回折格子９３２を配置すれば、ブラックマトリックスを目立ちにくくすることができる。回折格子９３２は拡大レンズ１３３６と液晶表示パネル１３３３間に配置している。また、液晶表示パネル１３３３の入射光側に配置してもよい。但し、配置位置により、回折格子９３２のピッチ、高さ等を変える必要がある事は言うまでもない。回折格子９３２はブラックマトリックスを見えにくくする効果がある。したがって、ブラックマトリックスが見えず滑らかな表示画像が得られる。
【０３１０】
回折格子９３２は透過型のものを用い、格子の断面形状はサインカーブ状、円弧状、台形状などが考えられる。回折格子９３２のパターンは１次元、２次元など多くの変形が考えられる。また、ピッチは、液晶表示パネル１３３３の画素の大きさが１００〜３０μｍで、回折格子９３２を液晶表示パネル１３３３の近くに配置する場合には、１００〜２０μｍの範囲が適当である。
【０３１１】
また、回折格子９３２を拡大レンズ１３３６の近くに配置する場合には、２〜０．１ｍｍが適当である。回折格子９３２の作製方法としては、ＳｉＯ２などの無機物質をガラス基板上に蒸着してパターニングする方法、ガラス基板上にポリマーとドーパントの混合物をスピンコートし、パターンマスクを介して露光した後、減圧加熱によってドーパントを昇華させる方法などがある。回折格子板はクラレ（株）等も製造・販売を行なっている。
【０３１２】
また、拡散板１５は図９９に示すように液晶表示パネル１３３３にはりつけてもよい。収縮機構としては液晶表示パネル１３３３を取付ホルダー９９１に取りつけ、ランプ１１をボデー１３２１に取りつけることにより、図９９、図１００に示すようにビューファインダの全長を収縮、伸縮させることができる。
【０３１３】
フレネルレンズ５５２の問題として、図１０２に示すようにフレネルレンズ５５２内でおこる界面反射がある。特に、入射光８７２がフレネルレンズ５５２の界面１０２２に入射すると図の点線で示すように界面１０２４，１０２３等で反射してしまう。その対策として図１０１に示すようにフレネルレンズ５５２の厚みｔを厚くする方法がある。フレネルレンズ５５２自身を厚くするのは物理的に困難である場合は、透明基板１０１１をフレネルレンズ５５２に透明樹脂９０１ではりつけるとよい。透明基板等の側面（有効表示範囲外、光が直接入射しない領域）に光吸収膜１０１２を塗布する。光吸収膜１０１２として黒色塗料等が例示される。
【０３１４】
以上のようにフレネルレンズ５５２を見かけ上厚くすることにより、図１０３に示すように光線８７２は界面１０３１で一度反射し、側面の黒色塗料１０１２に入射するのでフレネルレンズ５５２内でハレーションが生じない。なお、図１０１において、ｔとｄの関係はｄ／８＜ｔにすればハレーションはほとんど生じず良好な結果が得られた。
【０３１５】
ＰＤ液晶表示パネル１０４１を拡散板１５のかわりに用いれば、拡散度を自由に可変することができる。この構成の説明を図１０４に示す。
まず、拡散板１５のかわりに用いるＰＤ液晶表示パネル１０４１について説明する。ＰＤ液晶表示パネル１０４１は図２４の動作原理で動作することは先に説明をした。ガラス基板１０４５にはＩＴＯ電極１０４６が形成され、前記ＩＴＯ電極１０４６間にＰＤ液晶層１０４７が狭持されている。なお、１０４４は封止樹脂である。前記ＩＴＯ電極１０４６に電圧が印加されていない時は液晶層１０４７は散乱状態であり、電圧が印加されることによりＰＤ液晶層１０４７は透明状態となる。前記電圧の強弱によってＰＤ液晶層１０４７の拡散の程度は変化する。
【０３１６】
信号発生源１０４２は矩形波を出力し、前記矩形波は信号振幅可変器１０４３で信号振幅を変化させる。信号振幅の可変は抵抗Ｒｂで行う。矩形波の大きさが大きいほどＰＤ液晶層１０４７は透明状態となる。
【０３１７】
ランプ１１から放射された光５１はフレネルレンズ５５２で集光される。その光はＰＤ液晶表示パネル１０４１で光の直進度が変化させられる。したがってＰＤ液晶表示パネル１０４１は拡散板１５と同様にフレネルレンズ５５２の溝をみえにくくする効果を有する。さらに光透過率を変化することから、表示パネル１３３３の表示輝度を調整できるという効果も有する。
【０３１８】
ＰＤ液晶表示パネル１０４１の透過率が高いときは、液晶表示パネル１３３３は高輝度表示を行える。したがって、明るい所で表示画像をみるのに適している。逆にＰＤ液晶表示パネル１０４１の透過率が低いときは液晶表示パネル１３３３の表示画像は暗くなる。しかし、視野角は広くなるので、広範囲から液晶表示パネル１３３３を見る場合に適している。以上のように状況に応じて液晶表示パネル１３３３の表示状態を調整することができる。
【０３１９】
界面による光反射を防止するためには、図１０５に示すように拡散板１５とフレネルレンズ５５２等とを光結合剤ではりつければよい。光透過率が高まり、また界面でのハレーションも低減する。拡散板１５のかわりとしてＰＤ液晶表示パネル１０４１を用いる場合も、図１０６のようにすればよいことは言うまでもない。もちろん図１０６に示すように拡散板１５とＰＤ液晶表示パネル１０４１の両方を用いてもよい。
【０３２０】
なお、以前にも説明したが、図１０７に示すように拡散板１５のかわりに回折格子９３２を用いても拡散板としての機能をはたせることは言うまでもない。また、ランプ１１からの光の放射面積を変化させるために、図１０９のように絞り１０９１をもうける。絞り１０９１とはカメラのシャッタ虹採絞り，しぼり等に用いられるものが例示される。絞り１０９１の穴径を小さくするほど指向性は狭くなり液晶表示パネル１３３３の表示コントラストは向上する。逆に大きくすると指向性は広くなり液晶表示パネル１３３３の表示コントラストは低下するが表示画像は明るくなる。
【０３２１】
本発明に関連する参考例のビューファインダの構成は、拡大レンズ１３３６が有るものとして説明をしてきたがこれに限定されるものではない。たとえば、図１１０に示すように拡大レンズ１３３６がなくてもよい。この場合観察者が見ることができる表示画像は小さくなるが、液晶表示パネル１３３３サイズが一定以上（１インチ以上が見やすである）の場合は実用上問題がない。
【０３２２】
フレネルレンズ５５２等は透過型として説明してきたが、図１２１に示すように反射型のものを構成できることは言うまでもない。アルミ板等を加工することにより反射型フレネルレンズ１２１１を作製できる。また、ガラス樹脂で成型し、表面にＡｌ等の金属薄膜を蒸着したものでも作製できる。フレネルレンズ１２１１はランプ１１からおよび反射板８８３で反射された光を集光して略平行光にして液晶表示パネル１３３３を照明する。
【０３２３】
ランプ１１からの光は図１１１に示すように導光体１１１１を用いて集光手段（フレネルレンズ、照明レンズ５５２等）に照射させることができる。このように導光体１１１１を用いればランプ１１の配置位置には制約がなくなる。したがってわずかな空間にランプ１１をおけ、スペースの有効利用を行える。
【０３２４】
図１１２に示すように導光体１１１１の外面にＡｌ等の反射膜１１２１が形成され、前記導光体１１１１はランプ１１にかぶせられている。ランプ１１から放射された光は反射膜１１２１間で反射しながら導光体１１１１内を伝達され出射端から放射される。
【０３２５】
図１１２はランプ１１に導光体１１１１をかぶせるとしたが、これに限定するものではなく、図１１３（ａ）に示すようにランプ１１の先端に接着剤１０５１で取り付けてもよい。また、図１１３（ｂ）に示すように複数の光ファイバー１１３１をたばねたものを導光体として用いてもよい。
【０３２６】
図１１４は特に屋外を用いる際に外光（太陽光１１４１等）を用いて液晶表示パネル１３３３を照明する方式である。ビューファインダのボデー１３２１の頂上部には窓があけられ、フレネルレンズ１１４３がはめこまれている。フレネルレンズ１１４３はレンズ厚を薄くするために用いるものであり、許容される際には、プラスチックもしくはガラスレンズの正レンズにおきかえてもよい。太陽光１１４１はほぼ平行光であるから前記光はフレネルレンズ１１４３により集光され、ミラー７５１で反射されて光の進行方向が曲げられ、集光手段５５２に入射する。
【０３２７】
つまり、フレネルレンズ５５２は屋外光１１４１とランプ１１からの光の双方を集光する機能をもつ。
【０３２８】
ミラー７５１で反射される光の状態はランプ１１から放射される光と同様の状態となるような位置に配置される。当然のことながら、屋外光１１４１をボデー１３２１内にとりこまず、液晶表示パネル１３３３を照明する場合は、ランプ１１を発光させて、前記ランプ１１からの光を用いる。
【０３２９】
ランプ１１を発光させるかもしくは屋外光１１４１が弱いときには、補助的にランプ１１を発光させて、表示パネル１３３３に入射する単位面積あたりの光束量（輝度）を一定値にして用いる。ランプ１１を点灯させるか、もしくは点灯した発光輝度の明るさは、ボデー１３２１の頂上部等に配置したホトセンサ１１４２で屋外光１１４１の強弱を判断して決定をする。図１１５はその判断をする回路構成である。ホトセンサ１１４２としてはホトダイオード等が該当する。
【０３３０】
光検出回路１１５２はホトセンサ１１４２とオペアンプＡ_１等からなる積分回路から構成される。オペアンプＡ_１からは屋外光１１４１の強弱に応じて電圧Ｖが出力される。１１５１はヒステリシスコンパレータ回路であり、ヒステリシス状態を決定する抵抗Ｒ_２、Ｒ_３とオペアンプＡ_２およびリファレンス電圧Ｖ_５を発生させる電圧源から構成される。
【０３３１】
オペアンプＡ_１の出力電圧Ｖはリファレンス電圧Ｖ_５と比較される。Ｖが一定値以上のときオペアンプＡ_２の出力端子ａの電圧は＋電圧（もしくは−電圧）となる。前記電圧によりアナログスイッチＳＷ１１５３の接点は閉じ、電圧Ｅ_ａがアノード電極２５に印可されてランプ１１は点灯する。逆にオペアンプＡ_２の出力が−電圧（もしくは＋電圧）の点はアナログスイッチＳＷ１１５３はオープンとなる。
【０３３２】
ヒステリシスコンパレータ回路１１５１を用いたのはホトセンサ１１４２に入力する光１１４１には強弱が生じる（たとえば、ビデオカメラを使用中に太陽が雲の影にはいった場合等）のに対処するためである。外光の強弱によりそのつどコンパレータＡ_２の出力が変化するとランプ１１が点滅し、液晶表示パネル１３３３の表示画像が非常にみづらいからである。ヒステリシスコンパレータ回路１１５１を用いることにより、一度ランプ１１が点灯した後は、多少、屋外光１１４１ａが強くなっても消灯しない。したがって、点滅することはなくなる。
【０３３３】
図１１７は図１等に比較して、表示画面の大きい液晶表示パネル１３３３を用いたビューファインダの構成図である。ランプ１１は横置きにして、ビューファインダの全長を短くしている。理解を容易にするため遮光カバー１１７１と液晶表示パネル１３３３等とは離して図示しているが実際上に密着して配置される。遮光カバー１１７１は観察者が見る方向を規定するために用いられる。観察者があまり斜め方向から液晶表示パネル１３３３を見ようとすると、遮光カバー１１７１により液晶表示パネル１３３３の表示画面の周辺部が見えなくなる。
【０３３４】
そのため、観察者は液晶表示パネル１３３３の表示画像を前記画面の正面から見るように心がける。このように接眼カバー１３３３を配置するのはランプ１１から放射される光はフレネルレンズ５５２（又は集光レンズ）により指向性の狭い光に変換され、観察者は前記指向性の狭い光を見ることになるからである。指向性が狭いため液晶表示パネル１３３３の正面以外は急に画像が暗く見える。そのため遮光カバー１１７１を配置して、表示画像が明るく見える方向から見るように観察者を誘導するのである。
【０３３５】
ただし、拡散板１５を配置することにより視野角は拡大されている。拡散板１５の拡散度が高いほど視野角（見る角度により表示画像が見えなくなるまでの角度）が拡大される。しかし、表示画像は暗くなり、表示コントラストも低下してしまう。そのため、拡散板１５の拡散度をできるだけ低くする。そこで、遮光カバー１１７１を用いて、表示画像を良好に見ることができる角度を強制的に規定させるのである。このように構成することにより光源から放射される光を有効に利用し、消費電力を低減できるのである。
【０３３６】
液晶表示パネル１３３３の有効表示領域が大きい場合、あるいはフレネルレンズ５５２の焦点距離が長い場合は全長が長くなる場合があるので、図１１８に示すように、ミラー７５１を用いて光路８７２を屈曲させて構成すればよい。ランプ１１から放射される光はミラー７５１ｂで角度を屈曲されてフレネルレンズ５５２に入射する。
【０３３７】
図１１７では発光素子（ランプ１１）として、小型蛍光放電管１１を用いるものとして図示した。しかし、その発光素子は図８８に示すように小型蛍光管８８２等であってもよい。その小型蛍光管８８２として松下電器産業（株）が製造している品番Ｋ−Ｃ２１Ｔ２６Ｅ８５Ｈ、Ｋ−Ｃ３０Ｔ２６Ｅ８５Ｈ等がある。これらの蛍光管は冷陰極方式でランプ消費電力も０．３３Ｗ、０．４Ｗと少ない。前記蛍光管８８２から放射される光を有効に前面に出射できるように、蛍光管８８２の背面にかまぼこ状の反射板８８３を配置する。また、蛍光管８８２からの光を良好に集光するため平板状のシリニドカルレンズ８８１を配置する。発光手段が棒状の発光体であるため同心円状のフレネルレンズ５５２である必要はなくシリニドカルレンズ８８１でもよいからである。
【０３３８】
蛍光管８８２の前面から放射された光は直接シリニドカルレンズ８８１に入射し、集光されて液晶表示パネル１３３３に入射する。蛍光管８８２の後面から放射された光は反射板８３３で反射された後、シリニドカルレンズ８８１に入射して、液晶表示パネル１３３３に入射する。もちろん図１１７のように遮光カバー１１７１を配置してもよい。
【０３３９】
図８３では液晶表示パネル１３３３とフレネルレンズ５５２間の距離ｄ２を使用時に伸張して用いられるように構成している。図８７の構成でも同様のことを実施できる。図８７のように液晶表示パネル１３３３ｂを取り付けたケース８６１とランプ１１を取り付けたケース８７１とをジャバラ８６２ｂで結合し、前記ジャバラ８６２ｂを伸張、収縮させることにより表示パネル１３３３とフレネルレンズ５５２間を調整できるようにすればよい。
【０３４０】
図８７の構成では液晶表示パネル１３３３が大きいため、ランプ１１と集光レンズ５５２間に一定の距離が必要であるため、体積が大きい。これを解決するためには図８６のように構成すればよい。ビューファインダを不使用の場合は、図８６（ａ）のようにジャバラ８６２ａをおりたたんでおく。使用時は図８６（ｂ）のようにジャバラ８６２ａおよび８６２ｂを引きのばし、集光レンズ５５２の焦点位置にランプ１１の発光部がくるようにする。
【０３４１】
液晶表示パネル１３３３、拡散板１５、集光レンズ５５２はジャバラ８６２を介して一体として固定されている。ジャバラ８６２は外光が進入することも防止および、収縮のため等に用いるものであって、これに限定するものではない。たとえば、図８３に示すように伸縮自在の筒状（１３２１ｂ）のものであってもよい。
【０３４２】
観察者が液晶表示パネル１３３３の表示画像を見やすい方向に調整するのは容易である。回転軸８６３に回転可能なようにビスが固定されており、図８６（ｂ）の点線、実線のように自由に回転、固定できる。特にビデオカメラのモニタとして用いるとき有効である。ビデオカメラで被写体を良好に撮影（撮像）するためにはビューファインダの見る位置を変化させる必要があるからである。
【０３４３】
ランプ１１の頂点もしくは側面から放射される光を有効に利用するためには、図１１９のように構成すればよい。ランプ１１の頂点部から放射される光８７２は図１２０（ｂ）の光８７２ｄのようにミラー８８３ａで反射されて表示パネル１３３３に向かう。もちろん前面から放射される光８７２は直進して表示パネル１３３３に向かう。ランプ１１の側面から放射される光は、図１２０（ａ）に示すようにミラー８８３ｃ、８８３ｂで反射され表示パネル１３３３に入射する。図１２０のようにミラー８８３を用いて表示パネル１３３３に斜め方向からの光を入射させることにより観察者が表示パネル１３３３の表示画像を見る時の視角が広がる。つまり、多少眼の位置をずらせても表示画像が急に暗くなることがなくなる。
【０３４４】
図１２３のようにランプ１１ａ、１１ｂというように複数の発光素子を用い、それぞれの発光素子から放射される光を液晶表示パネル１３３３に斜めに（光線１２３２ａ、１２３２ｂ）入射させても視角をひろげることができる。したがって、本発明に関連する参考例のビューファインダにおいて、発光素子（ランプ１１）は１個に限定するものではない。複数の発光素子を用いることにより視角がひろがり、表示画像をみやすくなるという効果が発揮されるからである。
【０３４５】
以上の本発明に関連する参考例のビューファインダは、一枚の液晶表示パネル１３３３で構成されるものであった。しかし、本発明のビューファインダは、これに限定されず、例えば、図９５の構成のものをも含む。
【０３４６】
図９５において、９５２はＰＢＳ（偏光ビームスプリッタ）であり、多数の光学メーカーが発売している（たとえば、日本メレスグリオ様の０３ＰＢＳ０２５等）。ＰＢＳ９５２の光合成面９５１には誘電体薄膜が積層されＰ偏光またはＳ偏光を反射または通過する。
【０３４７】
液晶表示パネル１３３３ａで変調された光はＰＢＳ９５２の光合成面９５１で反射され（Ｐ偏光またはＳ偏光）拡大レンズ１３３６に入射する。一方、液晶表示パネル１３３３ｂで変調された光はＰＢＳ９５２の光合成面９５１を通過し（Ｓ偏光またはＰ偏光）拡大レンズ１３３６に入射する。観察者は２つの液晶表示パネル１３３６の画像を重ね合わせてみるため、画素数が２倍となる。したがって、高精細表示を実現できる。なお、ＰＢＳ９５２のかわりに光の半分を透過させるハーフミラーを用いてもよい。
【０３４８】
ハーフミラーを用いた場合は、ランプ１１ａから放射された光は液晶表示パネル１３３３ａに入射し、前記液晶表示パネル１３３３ａを出射した光がハーフミラー（図９５のＰＢＳ９５２をハーフミラーとおきかえて考えればよい）に入射する。ハーフミラーは前記光の半分を拡大レンズ１３３６側に反射する。一方、ランプ１１ｂから放射された光は、液晶表示パネル１３３３ｂに入射し、前記液晶表示パネル１３３３ｂを出射した光がハーフミラーに入射する。ハーフミラーは同様に前記光の半分を拡大レンズ１３３６側に反射する。液晶表示パネル１３３３ａの光学像と液晶表示パネル１３３３ｂの光学像は半画素だけ位置をずらして２つの光学像を重ね合わせる。
【０３４９】
液晶表示パネルはブラックマトリックスが形成されているため、一方の液晶表示パネル１３３３ａのブラックマトリックスの光学像上に、他方の液晶表示パネル１３３３ｂの画素の光学像を重ね合わせる。前述のように重ね合わせることにより、表示画像の精細度が向上する。２枚の液晶表示パネルの映像信号のサンプリングタイミングを半画素分ずらせることは言うまでもない。
【０３５０】
同様に液晶表示パネル１３３３が３つ以上の場合も考えられる。その構成を図１１６に示す。９５３はダイクロイックミラーである。ランプ１１ａは赤色に発光しているとし、前記ランプからの光は液晶表示パネル１３３３ａに入射する。液晶表示パネル１３３３ａには赤色の映像信号が印加されているものとする。前記液晶表示パネル１３３３ａで変調された赤色光はダイクロイックミラー９５３ａで反射され、拡大レンズ１３３６に入射する。ランプ１１ｂは緑色に発光しているとし、液晶表示パネル１３３３ｂには緑色の映像信号が印加されているとする。前記液晶表示パネル１３３３ｂで変調された緑色光はダイクロイックミラー９５３を通過し、拡大レンズ１３３６に入射する。またランプ１１ｃは青色に発光しているとし、液晶表示パネル１３３３ｃは青色の映像信号が印加されているものとする。前記液晶表示パネル１３３３ｃで変調されて青色光はダイクロイックミラー９５３ａで反射し、拡大レンズ１３３６に入射する。観察者（図示せず）は３つの液晶表示パネル１３３３で変調されダイクロイックミラー９５３で合成された画像を見ることになる。したがって画素数は１つの液晶表示パネル１３３３の３倍の画素数となり高精細の画像表示を実現できるのである。
【０３５１】
図１２０では２つのランプ１１を用いて視角を改善する構成について説明をした。しかし、１つのランプ１１で視角を適的な方向に調整する方法がある。この方法について図９６で説明をする。視角は観察者が最も見やすい方向に設定すればよい。視角を調整するにはランプ１１と液晶表示パネル１３３３の中心軸９６１から、レンズ５５２中心を変化させればよい。つまり中心軸がずれれば、液晶表示パネル１３３３に入射する主光線の角度はかたむく。したがって、フレネルレンズ５５２の位置をｘだけずらす、もしくは、ランプ１１の位置を少し中心軸９６１からずらせばよい。ずらすことにより観察者が最適に液晶表示パネル１３３３の表示画像がみえる位置に調整することができる。この技術的思想を、本発明に関連する参考例のビューファインダに適用することにより最適視方向に観察者が容易に調整できる。
【０３５２】
以上のことはビューファインダだけではなく、たとえば電話器に取り付けられた表示領域９７１にも適用できる。その説明図を図９７、図９８に示す。電話器の表示領域９７１には相手先の電話番号等が表示され、前記表示はセキュリティ上他の人にはみられたくはない。本発明に関連する参考例のランプ１１、集光レンズ５５２、表示パネル１３３３で構成される表示装置は表示画像が見える視角（視野角）が狭い。したがって、電話をかけている本人にしか見えず、セキュリティ上効果がある。しかし、視角が狭いため最適方向に主光線の方向をむけなければ、電話を使用する当人も表示領域９７１の表示画像が見えない。たとえば、図９８の場合、主光線の方向がａのとき、観察者Ａは表示画像が見えるが、それより背の低い観察者Ｂにはみえない。そこでランプ１１の位置、もしくは集光レンズ５５２の位置を矢印方向に移動させることにより観察者Ｂ（電話の使用者）のみがみえるようにすることができる。
【０３５３】
集光レンズ５５２の位置調整等はもちろん自動で行うこともできる。使用者が受話器９７４をとったとき、もしくはプッシュボタン部をおした時には電話本体９７３に近づいている。その時に電話器本体９７３にとりつけた赤外線ＬＥＤ９７５ａ−９７５ｄ（図９７（ｂ）参照）より赤外線を発生し、使用者にあたって反射する反射光を受光素子９７６で検出する。以上の作業により使用者の背の高さ等の概略を知ることができる。背の高さがわかれば、あらかじめ背の高さに対して設定してある移動量ｘだけ集光レンズ５５２を移動させればよい。
【０３５４】
図８３で説明したフレネルレンズ５５２および拡散シート１５を用いるという技術的思想はビューファインダのみに適用されるものではなく、図１２２（ａ）に示すような投射型表示装置にも適用できる。発光手段としてメタルハライドランプ１２２１ａが該当し、凹面鏡１２２１ｂおよびＵＶＩＲカットフィルタ１２２１ｃで照明光学系１２２１を構成する。フレネルレンズ５５２は前記照明光学系１２２１からの光を略平行光にして液晶表示パネル１３３３に入射させる。拡散シート１５、フレネルレンズ５５２の溝がスクリーン（図示せず）に投影されないようにするためのものである。投射レンズ１２２２は液晶表示パネル１３３３の変調画像をスクリーンに拡大投影する。
【０３５５】
図１２２（ａ）は液晶表示パネル１３３３にカラーフィルタ１２２３を具備させてカラー表示を行うものである。カラーフィルタ１２２３がなくとも、図１２２（ｂ）の構成でカラー画像を表示できる。照明光学系１２２１から放射された白色光はダイクロイックミラー９５３により青，緑，赤の３つの光に分離される。液晶表示パネル１３３３にはマイクロレンズ１２２５がマトリックス状に配置されたマイクロレンズアレイ１２２４がはりつけられている。１つのマイクロレンズ１２２５は３つの画素２４４（青，緑，赤の３つので１つの組）に対応する。前記青色光はマイクロレンズ１２２４により画素２４４ｂに入射し、緑光は画素２４４ｂ，赤色光は画素２４４ｃに入射する。したがって、カラーフィルタ１２２３がなくともカラー表示を行える。
【０３５６】
本実施の形態の技術的思想は他の装置にも適用できる。たとえば、図１２３に示すメガネなし立体表示装置（３Ｄディスプレイシステム）にも応用できる。１２３１はイメージスプリッタであり液晶表示パネル１３３３の１つ１つの画素に正しく位置合せされている。発光素子（ランプ１１ａ，１１ｂ）には、それぞれ反射ミラー８３３ａまたは８３３ｂが配置されており、フレネルレンズ５５２に向かって光を放射する。各発光素子はフレネルレンズ５５２の略焦点位置に配置される。
【０３５７】
ランプ１１ａの主光線１２３２ａは、フレネルレンズ５５２（もしくは液晶表示パネル１３３３）の法線に対し角度＋θ傾いている。一方、ランプ１１ｂの主光線１２３２ｂはフレネルレンズ５５２（もしくは液晶表示パネル１３３３）の法線に対し角度−θ傾いている。イメージスプリッタ１２３１は開口部１２４１と遮光部１２４２とが交互に形成されている（図１２４参照）。遮光部１２４２はマトリックス状あるいはストライプ状が例示される。
【０３５８】
図１２４は本実施の形態の３Ｄディスプレイシステムの説明図である。液晶表示パネル１３３３にはランプ１１からの光が入射する。主として主光線１２３２ａが右眼画像１２４４の画素を通過し、主光線１２３２ｂが左眼画像１２４３の画素を通過する。イメージスプリッタ１２３１の遮光部１２４２は観察者１２４５の左眼には右眼画像１２４４の画素を通過した光が到達しないように、かつ、右眼には左眼画像１２４３の画素を通過した光が到達しないようにする働きをもつ。また、イメージスプリッタ１２３１の開口部１２４１は観察者１２４５の左眼に左眼画像１２４３の画素を通過した光が到達するように、かつ、右眼には右眼画像１２４４の画素を通過した光が到達するようにする働きをもつ。当然に左眼画像１２４３の画素には左眼用の映像を右眼画像の画素には右眼用の映像を液晶表示パネル１３３３に表示させる。これは１画素ごとに右眼用の映像信号と左眼用の映像信号とをアナログスイッチ等で切りかえて、液晶表示パネル１３３３に入力する１つの映像信号とすれば実現できる。
【０３５９】
図１２４では小型蛍光放電管を発光素子として用いるとしたが、図５２に示すように平面蛍光ランプ５２１（たとえばウシオ電機（株）品番ＵＦＵ０７Ｅ８５２）を発光素子として用いることもできる（図１２５参照）。また、図５１のＬＥＤ等も用いることが出来る。図１２５に示すように、平面蛍光ランプ５２１には、裏面に昇圧コイル１２５１が接続されている。発光素子は１つでもよい。また、フレネルレンズ５５２のかわりにプラスチック等からなる凸レンズ１２５２等を用いてもよい。集光機能としては同様であるからである。凸レンズは平面、もしくは曲率半径の大きい面を平面蛍光ランプ５２１側に向ける。これは、正弦条件を満足しやすくして、液晶表示パネル１３３３の表示画像の輝度均一性を良好にするためである。
【０３６０】
ただし、凸レンズは平凸レンズに限定するものではなく両凸レンズでもよい。また、図１２３のイメージスプリッタ１２３１としてレンチキュラスクリーン（レンズ）を用いてもよい。レンチキュラスクリーンにはかまぼこ状のレンズが形成されており、前記レンズにより左眼用の透過光と右眼用の透過光とを選択制御できることにはかわりがないからである。たとえば、レンチキュラレンズ（レンチキュラスクリーン）を液晶表示パネル１３３３に付加した構成としては図１２７の構成が例示される。
【０３６１】
図１２３はイメージスプリッタ１２３１を用いて左眼用の光と右眼用の光とを分離するものであった。同一の機能は図１３４に示すようにプリズム板１３４１を用いても実現できる。プリズム板１３４１は三角状の板である。
【０３６２】
集光手段１２５２から出射された指向性の狭い光はプリズム板１３４１に入射し、スネルの法則に従って光の進行方向を変化させられる。一つのプリズム板１３４１の三角形には２つの隣接した画素電極２４４が対応している。プリズム板１３４１を通過する”点線”の光線は右眼用の画像を表示する画素２４４ｂを通過する。一方”実線”の光線は左眼用の画像を表示する画素２４４ａを通過する。したがって、プリズム板１３４１によって右眼用と左眼用の光が形成され、アクティブマトリックス型の液晶表示パネル１３３３は一画素ごとに交互に右眼用と左眼用を表示することにより観察者は立体（３Ｄ）表示を見ることができる。
【０３６３】
なお、プリズム板１３４１の三角形のつぎ目が目立つ場合はプリズム板１３４１と液晶表示パネル１３３３間もしくは液晶表示パネル１３３３の光出射側に散乱手段（拡散板１５）を配置すればよい。したがって、ビューファインダに拡散板１５を用いるという技術的思想が３Ｄにも生かされているのである。
【０３６４】
図１３４等はプリズム板１３４１を用いて右眼用の光を左眼用の光を形成するものであった。その他図１３５に示す方法によっても実現できる。
【０３６５】
図１３５において、ランプ１２２１ａからの光は放物面鏡１２２１ｂにより略平行光の光（指向性の狭い光）に変換され出射される。出射された光はＵＶＩＲカットフィルタ１２２１ｃにより赤外線と紫外線とがカットされて可視光のみが出射される。前記光はハーフミラー１３５１により半分の光が点線のように反射され、通過した光はミラー１３５２により実線のように反射される。なお、ハーフミラー１３５１とミラー１３５２はダイクロイックミラーもしくはダイクロイックプリズムであってもよい。
【０３６６】
液晶表示パネル１３３３にはマイクロレンズアレイ１２２５が光結合剤で貼り付けられており、２つの画素２４４ａ、２４４ｂに対して１つのマイクロレンズ１２２５が対応している。マイクロレンズ１２２５により点線の光は画素２４４ａを通過し、実線の光は画素２４４ｂを通過する。これが左眼用の光と右眼用の光となる。以上のように構成すれば、図１２４と同様に３Ｄ表示を行うことができる。
【０３６７】
以上の３Ｄディスプレイシステムは、一つの液晶表示パネル１３３３において一画素ごとに左眼用の画像と右眼用の画像を交互に表示するものであった。しかし、前記構成では片目について考えれば液晶表示パネルの画素数の１／２しか見えないことになる。つまり液晶表示パネルの画素数が１／２の表示画面をみているのと同様となる。
【０３６８】
この課題を解決する３Ｄディスプレイシステムの構成を図１２９に示す。イメージスプリッタ１２３１等に採用していない。２つのランプ１１の主光線が液晶表示パネル１３３３の法線に対してθの角度傾いている点、集光手段（レンズ１２５２）がランプ１１が放射する光を指向性の狭い光に変換する点は図１２３と同様である。つまり、主としてランプ１１ａからの光は左眼用の光となり、発光素子１１ｂからの光は右眼用の光となる。十分、液晶表示パネル１３３３から出射される光の指向性が狭いからである。液晶表示パネル１３３３としてはアクティブマトリックス型のＴＮ液晶表示パネルを採用する。
【０３６９】
図１３１は液晶表示パネル１３３３に印加する映像信号を作製する回路のブロック図である。再生装置ａ、再生装置ｂは、水平走査期間（Ｈ期間）で同期をとって映像信号を出力できるものである。同期は同期回路１３１１により行なう。これらの同期をとる方法、装置は映像分野の当事者であれば容易に構成できるので説明を省略する。再生装置ａおよびｂから読みだした映像信号は、Ａ／Ｄ変換器１３１３によりアナログ−デジタル変換され、ＳＲＡＭからなるメモリ１３１４ａ、１３１４ｂにデータとして保持される。メモリａ、ｂからは切り換え回路１３１５のスイッチを切り換えることにより選択的に読み出す。読み出された映像データはＤ／Ａ変換器１３１６によりデジタル−アナログ変換され、かつ水平同期信号等を付加されビデオ信号となり図１９のスイッチＳＷ１のａ端子に加えられる。
【０３７０】
メモリａからの読み出しは１フィールド（１Ｆ）の１／２期間（倍速読み出し）で読み出す。残りの１／２期間は０データ（映像データなし＝黒表示（無表示））がＤ／Ａ変換器１３１６に転送される。同様にメモリｂからの読み出しは１フィールド（１Ｆ）の１／２期間で読み出し、残りの１／２期間は０データ（映像データなし＝黒表示（無表示））がＤ／Ａ変換器１３１６に転送される。つまり、第１フィールドの１／２期間は左眼用の映像信号が、残りの１／２期間が無表示に、次の第２フィールドの１／２期間は右眼用の映像信号が、残りの１／２期間が無表示のビデオ信号がＤ／Ａ変換器１３１６から出力されるのである。なお、前述で１／２期間としたのは説明の便宜のためおよび回路構成の容易性のためであり、これに限定するものではない。たとえば３／４期間に映像信号が、残りの１／４期間が無表示であってもよい。また、１フィールドに限定するものでもなく、１フレームであってもよい。たとえば、１フレームの１／２期間（＝２フィールド）に左眼用の映像信号が、残りの１／２期間が無表示であってもよい。ただし、左眼用の映像信号が表示される間隔が長くなるとフリッカが発生する、あるいは表示画像に連続性がなくなり動画がぎこちなくなるという問題が発生する。静止画の場合は映像信号の表示間隔が長くなってもよいが動画表示の場合は問題となるであろう。この意味からも、左眼用の映像信号の出現間隔は１フレーム（＝２フィールド）ことが好ましい。
【０３７１】
図１３０は液晶表示パネル１３３３の画像表示状態と２つの発光素子１１ａ、１１ｂの点灯タイミング及び液晶表示パネル１３３３の画素電極に印加する信号極性とを図示したものである。
【０３７２】
まず、液晶表示パネル１３３３の表示状態について説明する（図の左から２列目）。（１）は無表示状態を示す（なお、無表示状態は、液晶表示パネルの有効表示領域を斜線で示す）。また、映像表示は説明を容易にするため”Ｆ”の文字を例とし、左眼用の表示は実線で右眼用の表示は点線で示すものとする。（２）において表示画面の上から順次映像が表示され、（３）は一画面全体が表示された状態を示す。次に（４）では画面の上方向から無表示状態となっていく。（５）は完全に無表示（黒表示）となった状態を示す。なお、（２）から（５）は量子的に移りかわるのではなく連続して行なわれる。つまり、液晶表示パネル１３３３はゲートドライブ回路（図示せず）が１水平走査期間（１Ｈ）ごとにゲート信号線にＴＦＴのオン電圧を印加し、順次、ゲート信号線にオン電圧を走査することにより行なう。
【０３７３】
（２）から（５）において任意の画素は１フィールド（１Ｆ）の期間の１／２時間映像表示されていることになる。また、この時は、左眼用発光素子１１ａが点灯（オン）し、右眼用発光素子１１ｂが消灯（オフ）する。したがって、液晶表示パネル１３３３には左眼用の映像表示されており、前記発光素子１１ａが放射する光により前記映像表示の光学像が観察者の左眼に到達する。黒表示（無表示）とするのは、アクティブマトリックス型液晶表示パネル（というよりは、液晶表示パネル）はメモリ性があるからである。メモリ性とは画素電極２４４に書き込まれた信号は、次に前記画素電極２４４に信号が印加されるまで保持される性質をいう。もし、黒表示を行なわなければ、左眼用の表示と右眼用の表示が液晶表示パネル１３３３に同時に表示される状態がおこるからである。同時に表示されれば左眼用ランプ１１ａと右眼用ランプ１１ｂを交互にオンオフさせても、左眼用の映像が右眼に、右眼用の映像が左眼に到達し、３Ｄ表示とはならない。図１３０に示すように、左眼用の映像を表示した後、いったんすべての画素電極２４４に保持された電圧をリセット（消去）し、新たに右眼用の映像を表示すれば、左眼用の映像と右眼用の映像をそれぞれ選択的に左眼、右眼に到達させることができる。
【０３７４】
（６）から（９）は右眼用の映像を表示していることを示している。その際左眼用ランプ１１ａは消灯（オフ）し、右眼用ランプ１１ｂが点灯（オン）させる。液晶表示パネル１３３３には画面の上端から右眼用の映像を表示させていき、（７）のように完全に右眼用の映像を表示させた後、（８）の如く上部より黒表示にしていく。上記（２）から（５）の状態（左眼用の映像表示状態）と、（６）から（８）の状態（右眼用の映像表示状態）を１フレームごとに繰り返す。
【０３７５】
なお、左眼用ランプ１１ａは（２）の表示状態で点灯させるとしたがこれに限定するものではなく、（１）の表示状態のように点灯させてもよい。同様に右眼用ランプ１１ｂは（５）の表示状態で点灯させてもよい。
【０３７６】
図１３０の左端欄は画素電極２４４に印加する信号の極性を示している。対向電極２４３の電位に対して正極性を”＋”で、負極性を”−”で示している。一画素電極２４４の行（横方向）には同一極性の信号を印加する。また、一行ごとに極性を反転させる。つまり、図１３０（ａ）において画素電極７４ａと７４ｂとは同一極性が、画素電極２４４ａと２４４ｃとは反対極性の信号が印加される。
【０３７７】
次のフィールド（図１３０（ｂ））では各画素電極の信号極性は、前のフィールド（図１３０（ａ））と逆となるようにする。つまり、図１３０（ａ）の画素電極２４４ｃは”−”極性が印加されているが、図１３０（ｂ）では”＋”極性が印加される。このように１フィールドごとに画素電極２４４に印加する信号極性を反転させることにより、フリッカの発生を防止でき、良好な画像表示を実現できる。
【０３７８】
図１３０は集光手段（レンズ１２５２）を用いて、ランプ１１ａが放射する光を左眼に、ランプ１１ｂが放射する光を右眼に入射させるものであった。前記集光手段のかわりに図１２７に示すようにレンチキュラレンズ１２７１を用いても、同様の３Ｄ表示を実現できる。なお、液晶表示パネル１３３３の映像表示状態および発光素子（ランプ１１ａ、１１ｂ）の発光状態等に図１３０に示したのと同様である。ただし、ランプ１１ａと１１ｂはいれかえて考える必要があるが基本的な問題はない。
【０３７９】
図１２８にレンチキュラレンズ１２７１部を通過する光路等の説明図である。レンチキュラレンズ１２７１ａは光結合剤９０１ａを介してアレイ基板２４２とオプティカルカップリング（ＯＣ）されており、また、レンチキュラレンズ１２７１ｂは光結合剤９０１ｂを介して対向基板２４１とＯＣされている。これは界面反射等を防止する等のためである。
【０３８０】
ランプ１１ａから放射された光（実線）はレンチキュラレンズ１２７１ａに入射し、液晶表示パネル１３３３の画素電極２４４を通過してかつ、レンチキュラレンズ１２７１ｂで屈折されて右眼に入射する。一方、ランプ１１ｂから放射された光（点線）はレンチキュラレンズ１２７１ａに入射し、同様に液晶表示パネル１３３３の画素電極２４４を通過し、かつレンチキュラレンズ１２７１ｂで屈折されて左眼に入射する。
【０３８１】
以上のことから、ランプ１１ａと１１ｂから放射される光は右眼および左眼に選択的に到達させることができることが理解できる。つまりレンチキュラレンズ１２７１は図１２９の集光手段（レンズ１２５２）と同様の機能を有する。したがって、図１３０の表示方法を実施すれば３Ｄ表示を行えるのである。
【０３８２】
ランプを２つ具備するという技術的思想は図１３９の構成でも実現できる。遮光板１３９３、遮光パターン１３９２には、１つのマイクロレンズ１２２５に対し、２つの微小穴（１３９１ａ、１３９１ｂ）を形成されている。穴１３９１ａから放射する光をマイクロレンズ１２２５により右眼用の光とし、穴１３９１ｂから放射する光を同様にマイクロレンズ１２２５により左眼用の光とする。以上のようにすれば１枚のマイクロレンズアレイ１２２４で指向性の良好な左眼用の光と右眼用の光を作製できる。またマイクロレンズアレイでなくとも図１２６のセルホック（円筒）レンズアレイでも実現できる。
【０３８３】
本発明に関連する参考例の３Ｄディスプレイでは点光源とみなせるランプ１１を用いているため、液晶表示パネル１３３３を出射する光の指向性が狭い。したがって、左眼用と右眼用の光を良好に分離することができる。また、２つのランプ１１から放射される主光線の角度を＋θおよび−θとすることにより、観察者が液晶表示パネル１３３３の画面中央部で良好に表示画像を見ることができる。また、主光線の角度を変化させることは容易である。また、ランプ１１の位置を変化させることも容易である。たとえば、図３３の点線位置に発光素子（ランプ１１）を移動させれば、表示パネル２２３の表示画像を斜め方向からみたときに３Ｄ表示になるようにすることができる。
【０３８４】
ランプを２つ具備する３Ｄディスプレイシステムでは、観察者が最適に３Ｄ画像を見えるように調整することが容易である。図１３２に示すようにランプ１１から放射される角度θを調整すればよい。たとえば、図１３２（ａ）で示すように表示パネル１３３３の表示画面から観察者の眼１４０１が比較的離している時（比較的遠くから表示画面を見ている時）は角度θ_１を小さくする。一方、図１３２（ｂ）のように観察者の眼１４０１が比較的、表示画面に近いときは角度θ２を大きくすればよい。
【０３８５】
より具体的に図１３３のように構成をする。アーム１４１２ａ、１４１２ｂには反射ミラー８３３を有するランプ１１がビス１４１１ａ、１４１１ｂが取り付けられており、前記アーム１４１２の一端はビス１４１１ｃで調整板１４１４に取り付けられている。また、ビス１４１１ａ、１４１１ｂによりスライド板１４１３の穴にアーム１４１２が取り付けられている。
【０３８６】
調整板１４１４を右方向に引っぱることにより２つのランプ１１間がひらく。また、押し込むことによりランプ１１間の距離はせばまる。以上のように調整板１４１４を観察者が調整することにより、最適に３Ｄ表示が見られるようにすることが容易にできる。
【０３８７】
上述のビューファインダは、発光素子の小さな発光体から広い立体角に放射される光をフレネルレンズ又は放物面鏡等で平行に近く指向性の狭い光に変換し、液晶表示パネル１３３３で変調して画像を表示するので、消費電力が少なく、輝度むらも少ない。しかも、ランプ１１の駆動回路も従来のビューファインダのようにバックライトを用いるものに比較して単純な構成となるため、コンパクトで軽量のビューファインダを提供できる。液晶表示パネルとしてＰＤ液晶表示パネルを用いれば、ＴＮ液晶表示パネルに比較して消費電力をさらに低減できる。また、フレネルレンズ５２２等と液晶表示パネル１３３３間に拡散板１５を配置することにより、液晶表示パネル１３３３の画素２４４とフレネルレンズ５２２の溝とが干渉してモアレを生ずることを、また、フレネルレンズの溝が視覚的に認識されることを抑制できるから良好な画像表示を実現できる。その上、拡散板１５をＰＤ液晶表示パネルとすることにより任意の視野角および表示画像のブライトネス（輝度、明るさなど）調整を行なうことができる。また、ランプ１１として点光源とみなせるものを使用できるから、良好な３Ｄ表示をも実現できる。
【０３８８】
【発明の効果】
低消費電力の液晶表示装置とこれを用いたビューファインダを提供することができる。
【図面の簡単な説明】
【図１】本発明に関連する参考例のビューファインダの断面図である。
【図２】本発明に関連する参考例のビューファインダの光源部の断面図である。
【図３】本発明に関連する参考例のビューファインダの光源部の断面図である。
【図４】本発明に関連する参考例のビューファインダの光源部の断面図である。
【図５】本発明に関連する参考例のビューファインダの説明図である。
【図６】本発明に関連する参考例のビューファインダの光源部の断面図である。
【図７】本発明に関連する参考例のビューファインダの光源部の説明図である。
【図８】本発明に関連する参考例のビューファインダの光源部の断面図である。
【図９】本発明に関連する参考例のビューファインダのランプの説明図である。
【図１０】本発明に関連する参考例のビューファインダのランプの説明図である。
【図１１】本発明に関連する参考例のビューファインダのランプの説明図である。
【図１２】本発明に関連する参考例のビューファインダのランプの説明図である。
【図１３】本発明に関連する参考例のビューファインダのランプの説明図である。
【図１４】本発明に関連する参考例のビューファインダのランプの説明図である。
【図１５】本発明に関連する参考例のビューファインダの説明図である。
【図１６】本発明に関連する参考例のランプの駆動方法の説明図である。
【図１７】本発明に関連する参考例のランプの駆動方法の説明図である。
【図１８】本発明に関連する参考例のランプの駆動方法の説明図である。
【図１９】本発明に関連する参考例のランプの駆動方法の説明図である。
【図２０】本発明に関連する参考例のランプの駆動方法の説明図である。
【図２１】本発明に関連する参考例のビューファインダの説明図である。
【図２２】本発明に関連する参考例のビューファインダの説明図である。
【図２３】高分子分散液晶表示パネルの断面図である。
【図２４】高分子分散液晶表示パネルの説明図である。
【図２５】本発明に関連する参考例のビューファインダの光源部の断面図である。
【図２６】本発明に関連する参考例のビューファインダの光源部の断面図である。
【図２７】本発明に関連する参考例のビューファインダの断面図である。
【図２８】本発明に関連する参考例のビューファインダのランプの説明図である。
【図２９】本発明に関連する参考例のビューファインダのランプの断面図である。
【図３０】本発明に関連する参考例のビューファインダのランプの断面図である。
【図３１】本発明に関連する参考例のビューファインダのランプの説明図である。
【図３２】本発明に関連する参考例のビューファインダの光源部の説明図である。
【図３３】本発明に関連する参考例のビューファインダの光源部の説明図である。
【図３４】本実施の形態のビューファインダの光源部の説明図である。
【図３５】本発明に関連する参考例のビューファインダの光源部の説明図である。
【図３６】本発明に関連する参考例のビューファインダの光源部の説明図である。
【図３７】本発明に関連する参考例のビューファインダのランプの説明図である。
【図３８】本発明に関連する参考例のビューファインダの光源部の斜視図である。
【図３９】本発明に関連する参考例のビューファインダの光源部の斜視図である。
【図４０】本発明に関連する参考例のビューファインダの光源部の斜視図である。
【図４１】本発明に関連する参考例のビューファインダの光源部の斜視図である。
【図４２】本発明に関連する参考例のランプの駆動方法の説明図である。
【図４３】本発明に関連する参考例のビデオカメラの説明図である。
【図４４】本発明に関連する参考例のビデオカメラの説明図である。
【図４５】本発明に関連する参考例のランプの駆動方法の説明図である。
【図４６】本発明に関連する参考例のランプの駆動方法の説明図である。
【図４７】本発明に関連する参考例のビューファインダのランプの説明図である。
【図４８】本発明に関連する参考例のビューファインダの光源部の説明図である。
【図４９】本発明に関連する参考例のビューファインダのランプの駆動方法の説明図である。
【図５０】ＬＥＤの説明図である。
【図５１】ＬＥＤの説明図である。
【図５２】蛍光面発光素子の説明図である。
【図５３】本発明に関連する参考例のビデオカメラの説明図である。
【図５４】本発明に関連する参考例の電子スチルカメラの説明図である。
【図５５】本発明に関連する参考例のビューファインダの断面図である。
【図５６】本発明に関連する参考例のビューファインダの断面図である。
【図５７】本発明に関連する参考例のビューファインダの説明図である。
【図５８】本発明に関連する参考例のビューファインダの説明図である。
【図５９】本発明に関連する参考例のビューファインダの説明図である。
【図６０】本発明に関連する参考例のビューファインダの説明図である。
【図６１】本発明に関連する参考例のビューファインダの説明図である。
【図６２】本発明に関連する参考例の表示装置の説明図である。
【図６３】本発明に関連する参考例の表示装置の説明図である。
【図６４】本発明に関連する参考例のビューファインダの説明図である。
【図６５】本発明に関連する参考例のビューファインダの説明図である。
【図６６】本発明に関連する参考例のビューファインダの説明図である。
【図６７】本発明に関連する参考例のビューファインダの説明図である。
【図６８】本発明に関連する参考例のビューファインダの説明図である。
【図６９】本発明に関連する参考例のビューファインダの説明図である。
【図７０】本発明に関連する参考例のビューファインダの説明図である。
【図７１】本発明に関連する参考例のビューファインダの説明図である。
【図７２】本発明に関連する参考例のビューファインダの説明図である。
【図７３】本発明に関連する参考例のビューファインダの説明図である。
【図７４】本発明に関連する参考例のビューファインダの説明図である。
【図７５】本発明に関連する参考例のビューファインダの説明図である。
【図７６】本発明に関連する参考例のビューファインダの説明図である。
【図７７】本発明に関連する参考例のビューファインダの説明図である。
【図７８】本発明に関連する参考例のビューファインダの説明図である。
【図７９】本発明に関連する参考例のビューファインダの説明図である。
【図８０】本発明に関連する参考例のビューファインダの説明図である。
【図８１】本発明に関連する参考例のビューファインダの説明図である。
【図８２】本発明に関連する参考例のビューファインダの斜視図である。
【図８３】本発明に関連する参考例のビューファインダの断面図である。
【図８４】本発明に関連する参考例のビューファインダの断面図である。
【図８５】本発明に関連する参考例のビデオカメラの説明図である。
【図８６】本発明に関連する参考例のビューファインダの説明図である。
【図８７】本発明に関連する参考例のビューファインダの説明図である。
【図８８】本発明に関連する参考例のビューファインダの説明図である。
【図８９】本発明に関連する参考例のビューファインダの光源部の説明図である。
【図９０】本発明に関連する参考例のビューファインダの光源部の説明図である。
【図９１】本発明に関連する参考例のビューファインダの光源部の説明図である。
【図９２】本発明に関連する参考例のビューファインダの説明図である。
【図９３】本発明に関連する参考例のビューファインダの説明図である。
【図９４】本発明に関連する参考例のビューファインダの説明図である。
【図９５】本発明に関連する参考例のビューファインダの断面図である。
【図９６】本発明に関連する参考例のビューファインダの説明図である。
【図９７】本発明に関連する参考例の表示パネルの説明図である。
【図９８】本発明に関連する参考例のビューファインダの説明図である。
【図９９】本発明に関連する参考例のビューファインダの断面図である。
【図１００】本発明に関連する参考例のビューファインダの断面図である。
【図１０１】本発明に関連する参考例のビューファインダの説明図である。
【図１０２】本発明に関連する参考例のビューファインダの説明図である。
【図１０３】本発明に関連する参考例のビューファインダの説明図である。
【図１０４】本発明に関連する参考例のビューファインダの説明図である。
【図１０５】本発明に関連する参考例のビューファインダの説明図である。
【図１０６】本発明に関連する参考例のビューファインダの説明図である。
【図１０７】本発明に関連する参考例のビューファインダの断面図である。
【図１０８】本発明に関連する参考例のビューファインダの断面図である。
【図１０９】本発明に関連する参考例のビューファインダの断面図である。
【図１１０】本発明に関連する参考例のビューファインダの断面図である。
【図１１１】本発明に関連する参考例のビューファインダの断面図である。
【図１１２】本発明に関連する参考例のビューファインダの説明図である。
【図１１３】本発明に関連する参考例のビューファインダの説明図である。
【図１１４】本発明に関連する参考例のビューファインダの説明図である。
【図１１５】本発明に関連する参考例のビューファインダの説明図である。
【図１１６】本発明に関連する参考例のビューファインダの断面図である。
【図１１７】本発明に関連する参考例のビューファインダの斜視図である。
【図１１８】本発明に関連する参考例のビューファインダの断面図である。
【図１１９】本発明に関連する参考例のビューファインダの断面図である。
【図１２０】本発明に関連する参考例のビューファインダの説明図である。
【図１２１】本発明に関連する参考例のビューファインダの説明図である。
【図１２２】本発明に関連する参考例の表示装置の構成図である。
【図１２３】本実施の形態の表示装置の説明図である。
【図１２４】本実施の形態の表示装置の説明図である。
【図１２５】本実施の形態の表示装置の説明図である。
【図１２６】本実施の形態の表示装置に用いるレンズの説明図である。
【図１２７】本実施の形態の表示装置の説明図である。
【図１２８】本実施の形態の表示装置の説明図である。
【図１２９】本発明に関連する参考例の表示装置の説明図である。
【図１３０】本実施の形態の表示装置の説明図である。
【図１３１】本発明に関連する参考例の表示装置の駆動方法の説明図である。
【図１３２】本発明に関連する参考例の表示装置の駆動方法の説明図である。
【図１３３】本発明に関連する参考例の表示装置の説明図である。
【図１３４】本発明に関連する参考例の表示装置の説明図である。
【図１３５】本発明に関連する参考例の表示装置の構成図である。
【図１３６】ビューファインダの外観図である。
【図１３７】従来のビューファインダの断面図である。
【図１３８】従来のビューファインダの光源部の説明図である。
【図１３９】本発明に関連する参考例のビューファインダの説明図である。
【図１４０】本発明に関連する参考例のビューファインダの設計例である。
【図１４１】本発明に関連する参考例のビューファインダの設計例である。
【図１４２】本発明に関連する参考例のビューファインダの設計例である。
【図１４３】本発明に関連する参考例のビューファインダの設計例である。
【図１４４】本発明に関連する参考例のビューファインダの放物面鏡の設計例である。
【符号の説明】
１１ ランプ
１２ 放物面鏡
１４ ベース基板
１５ 拡散（散乱）シート
１６ ランプ電位端子
１６ａ，ｂ フィラメント端子
１６ｃ アノード端子
１７ ランプ用回路部品
２０ 封止部材
２１，２１ａ ランプケース
２２ 反射面
２３ 蛍光体
２４ フィラメント
２５ アノード電極
２６ 緩衝部材
２７ ソケット
２８ 端子
２９ ハンダ
３０，３０ａ 突起
３１ 反射膜
３２ 光反射筒
１５ａ 拡散板
４３ エンボス加工面
５１ 光線
５２ 有効表示領域
７１ 低輝度部
７２ ゴムキャップ
７３ 突起
９１ 反射膜
１０１ 集光キャップ
１０２ 集光プリズム
１０３ 接着剤
１０４ 透明樹脂
１０５ 反射筒
１０６ 拡散板
１０７ 反射キャップ
１１１ 透明導電膜（ＩＴＯ）
１１２ 帯電防止膜
１２１ 導線
１３１ 金網
１６１ タイマー回路
１６２ 可変電源
１６３ 可変抵抗（可変電流素子）
１７１ インバータ
１７２ａ，ｂ アナログスイッチ
１７３ａ，ｂ 電流制限抵抗
１８１ ホトセンサ
１８２ オペアンプ
１８３ 光検出回路
１８４ 発振回路
１８５ 増幅器
１９１ アンプ
１９２ 位相分割回路
１９３ 出力切り換え回路
１９４ ドライブ回路制御部
１９５ ソースドライブ回路
１９６ ゲートドライブ回路
１９７，１９８ 電源
２０１ａ，ｂ ＤＣＤＣコンバータ
２０２ バッテリー
２０４ 電流検出回路
２１１ 外ワク
２１２ 絞りつまみ
２１３ 虹彩絞り
２４９ ソース信号線
２３０ カラーフィルタ
２３１ 透明樹脂
２４１ 対向電極基板
２４２ アレイ基板
２４３ 対向電極
２４４ 画素電極
２４５ 水滴状液晶
２４６ ポリマー
２４７ 入射光
２４８ 光変調層（液晶層）
２９１ 保護膜（ＳｉＯ_２）
３０１ 取付ガラス
３１１ 発光領域
３１２ マーカ
３１３ くぼみ部
３１４ 透明突起
３３１ 拡散（散乱）部
３３２ 拡散（散乱）点
３８１ 透明ホルダー（樹脂樹脂）
３８２ ホルダー固定部
３９１ 放物面鏡
４０１ 凸部
４１１ 拡散（散乱）板
４２１ サーミスタ
４２２ コンパレータ
４２３ ＣＰＵ
４２４ スイッチ回路
４２５ オペアンプ
４２６ ＦＥＴ
４３１ ビデオカメラ本体
４３２ 撮像レンズ部
４３３ スイッチ（ＳＷ）
４３４ 接続部
４３５ 録画スイッチ
４７１ 封止樹脂
５０１ 端子
５０２ 発光体
５０３ 樹脂レンズ
５０４ レンズ面
５０５ レンズ面の頂点
５０６ レンズ面の法線
５０７ レンズ面の曲率中心
５０８ レンズ面による発光体の像
５２１ 面発蛍光ランプ
５３１ ＣＣＤセンサ
５３２ 発光素子電源回路
５３３ 液晶表示パネル駆動回路
５３４ 再生回路
５４１ スチルカメラ本体
５５１ 反射板
５５２ 照明レンズ（凸レンズ）
５５３ 補助レンズ
６０１ レンズ面
６０２ フレネル面
６０３ 凸レンズ
６０４ フレネルレンズ
６１１ 平面部
６２１ 導光板
６２２ 拡散部
６３１ プリズム板
６４１ アイポイント
６８１ パネルホルダー
６９１ 表示部
７１１ ソケット
７１２ つまみ
７１３ 収縮部１
７１４ 収縮部２
７１５ 光軸
７５１ ミラー
８１１ 挿入部
８２１ つまみ
８３１ 反射板
１３３６ｂ 凹レンズ
８５１ 留め具
８６１ パネル取付部
８６２ ジャバラ
８６３ 回転軸
８６４ レンズ取付部
８７１ ケース
８７２ 光線
８８１ シリンドリカルレンズ
８８２ 小型蛍光管
８８３ 反射板
９０１ 透明接着剤
９１１ だ円面鏡
９１２ 遮光板
９２１ 拡散部
９３１ 円形絞り
９３２ 回折格子
９５１ 光合成面
９５２ ＰＢＳ
９５３ ダイクロイックミラー
９６１ 光軸
９７１ 表示領域
９７２ プッシュボタン部
９７３ 電話器本体
９７４ 受話器
９７５ 赤外線ＬＥＤ
９７６ 受光素子
９９１ 取付ホルダー
１０１１ 透明基板
１０１２ 光吸収膜
１０２２，１０２３，１０２４，１０３１ 界面
１０３１ 界面
１０４１ ＰＤ液晶表示パネル
１０４２ 信号発生源
１０４３ 信号振幅可変器
１０４４ 封止樹脂
１０４５ ガラス基板
１０４６ ＩＴＯ電極
１０４７ ＰＤ液晶層
１０５１ 光結合層
１０９１ 絞り
１１１１ 導光体
１１２１ 反射膜
１１３１ 光ファイバー
１１４１ 太陽光
１１４２ ホトセンサ
１１４３ フレネルレンズ
１１５１ ヒステリシスコンパレータ回路
１１５２ 光検出回路
１１５３ スイッチ回路
１１７１ 遮光カバー
１２１１ 反射型フレネルレンズ
１２２１ 光源
１２２１ａ メタルハライドランプ
１２２１ｂ 凹面鏡
１２２１ｃ ＵＶＩＲカットミラー
１２２２ 投射レンズ
１２２３ カラーフィルタ
１２２４ マイクロレンズアレイ
１２２５ マイクロレンズ
１２３１ イメージスプリッタ
１２３２ 主光線
１２４１ 開口部
１２４２ 遮光部
１２４３ 左目画像
１２４４ 右目画像
１２４５ 観察者
１２５１ 昇圧コイル
１２５２ 集光レンズ（凸レンズ）
１２６１ セルホックレンズ
１２７１ レンチキュラレンズ
１３１１ 同期回路
１３１２ 再生装置
１３１３ Ａ／Ｄ変換回路
１３１４ フレームメモリ
１３１５ 切り換え回路
１２１６ Ｄ／Ａ変換回路
１４０１ａ 右眼
１４０１ｂ 左眼
１４１１ ビス
１４１２ アーム
１４１３ スライド板
１４１４ 調整板
１３４１ プリズム板
１３５１ ハーフミラー
１３５２ ミラー
１３２１ ボデー
１３２３ 取付金具
１３３１ 蛍光管ｂｏｘ
１３３２ 接眼カバー
１３３３ 液晶表示パネル
１３３４ 偏光板
１３３５ 取付ホルダー
１３３６ 拡大レンズ
１３４１ 蛍光管の発光パターン[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a liquid crystal display device and a view finder using the same.
[0002]
[Prior art]
Liquid crystal display panels have been actively researched and developed because they are more likely to be lighter and thinner than display devices using CRTs. In recent years, twisted nematic mode (TN mode) liquid crystal display devices that apply the optical rotation of liquid crystal to image display have been put into practical use, and are used in portable pocket televisions, viewfinders of video cameras, and the like.
[0003]
Hereinafter, a conventional viewfinder will be described. In this specification, at least a light source (light generating means) such as a light emitting element and an image display device (light modulating means) such as a liquid crystal display panel are provided. Call. Therefore, the viewfinder of the present invention does not mean only the viewfinder of the video camera. For example, a display device such as a pocket television, an image display device of an electronic still camera, and a head mounted display are also included. Further, the light source includes all light sources that emit light by themselves, such as a hot cathode lamp, a cold cathode lamp, a PDP, and an LED.
[0004]
FIG. 136 shows an example of the appearance of the viewfinder. FIG. 137 shows a cross-sectional view of a conventional viewfinder. 1321 is a body, 1322 is an eyepiece cover, 1335 is an eyepiece ring, and 1333 is a twisted nematic (TN) liquid crystal display panel. A polarizing plate 1334 is disposed on the input / output surface of the liquid crystal display panel 1333. The body 1321 stores a liquid crystal display panel 1333 and a backlight 1331 as a light source. The magnifying lens 1336 is arranged inside the eyepiece ring 1335. By adjusting the degree of insertion of the eyepiece ring 1335, the focus can be adjusted according to the eyesight of the observer.
[0005]
The TN liquid crystal display panel 1333 has a liquid crystal layer 248 with a thickness of about 4 to 5 μm and has a mosaic color filter. A polarizing plate 1334 functioning as a polarizer 1334a and an analyzer 1334b is provided on both sides of the TN liquid crystal display panel 1333. The viewfinder is attached to the video camera main body 421 by a mounting bracket 1323. In the drawings, some parts are omitted, enlarged, and / or reduced to facilitate understanding, explanation, and / or drawing. For example, in the sectional view of the viewfinder in FIG. 136, the eyepiece cover 1322 and the like are omitted. The same applies to the following drawings.
[0006]
FIG. 138 is a perspective view of the main elements shown in FIG. The light source includes a fluorescent tube box 1331 in which a fluorescent tube is disposed, and a diffused light scattering plate 1332 disposed on the entire surface. The diffusion plate 1332 is used to diffuse the light emitted from the fluorescent plate box 1331 to make the surface light source with uniform luminance.
[0007]
A rod-shaped fluorescent tube is used as a light generating means of a conventional view finder. When the diagonal length of the display screen of the liquid crystal display panel 1333 is as small as about 1 inch, a fluorescent tube having a diameter of 2 to 5 mm is used. When the diagonal length of the display screen of the liquid crystal display panel 1333 is 1 inch or more, a plurality of the fluorescent tubes are often used. Light is emitted forward and backward from the fluorescent tube. A diffusion plate is provided between the fluorescent tube and the TN liquid crystal display panel 1333. The diffusion plate 1332 diffuses the light from the fluorescent tube and turns it into a surface light source. A surface light source is formed by the diffusion plate 1332, and light from the surface light source enters the liquid crystal display panel 1332. The light divergence area of the surface light source is equal to or larger than the image display area (effective display area) of the liquid crystal display panel 1333. Note that there is also a light emitting element that forms a surface light source without using a fluorescent tube and a diffusion plate 1332. It is usually called a flat fluorescent lamp, and is manufactured and sold by Ushio Inc. (eg, UFU07F852, etc.).
[0008]
Polarizing plates 1334a and 1334b are arranged before and after the liquid crystal display panel 1333. A polarizing plate 1334a (polarizer) disposed between the diffusion plate 1332 and the TN liquid crystal display panel 1333 has a function of converting random light from a surface light source into linearly polarized light. A polarizing plate 1334b (analyzer) disposed between the TN liquid crystal display panel 1333 and the viewer of the display screen has a function of blocking the light according to the degree of modulation of the light incident on the TN liquid crystal display panel 1333. Usually, the polarizer 1334a and the analyzer 1334b are arranged so that the polarization directions are orthogonal (normally white display).
[0009]
As described above, light from the light emitting element is scattered by the diffusion plate 1334, and a surface light source is formed. Light from the surface light source is converted into linearly polarized light by the polarizer 1334a. The TN liquid crystal display panel 1333 modulates the linearly polarized light based on an applied video signal. The analyzer 1334b blocks or transmits light according to the degree of modulation. The image is displayed as described above. The displayed image can be enlarged and viewed by a magnifying lens 1335 disposed between the analyzer 1334b and the observer.
[0010]
[Problems to be solved by the invention]
Video cameras are required to be compact and lightweight in terms of portability and operability. Therefore, a liquid crystal display panel is being introduced as a viewfinder display. However, at present, the power consumption of a viewfinder using a liquid crystal display panel is considerably large. For example, the power consumption of a viewfinder using a TN liquid crystal display panel having an effective display area of 0.7 inches is 0.4 W for the TN liquid crystal display panel and its driving circuit, and about 0.6 W for the light source. 0.0W. Video cameras have a limited battery capacity in order to ensure compactness and lightness. If the power consumption of the viewfinder is large, the continuous use time becomes short, which is a serious problem. In recent years, in particular, there has been a demand for miniaturization of video cameras, and accordingly, the battery capacity that can be loaded has been limited, and it has become increasingly indispensable to realize low power consumption of viewfinders.
[0011]
In addition, the light box 1331 including the fluorescent tube and the reflection plate needs to be a surface light source with less uneven brightness. Therefore, a diffusion plate 372 is arranged between the TN liquid crystal display panel 1333 and the fluorescent tube. When the diffusion plate 1334 having a low light diffusion degree is used, a light emission pattern 1341 of the fluorescent tube appears as shown in FIG. 57, which is seen through the display screen of the liquid crystal display panel 1333, and deteriorates the display quality. For this reason, a diffuser 1334 having a high degree of diffusion is used. Generally, when the degree of diffusion is increased, the light transmittance of the diffuser 1334 decreases. The only way to obtain the required brightness is to increase the amount of light output from the light source. This causes an increase in power consumption of the light source.
[0012]
Another problem is the size of the light emitting element. In order to obtain a surface light source, at least the light emitting area needs to be larger than the area of the effective display area of the liquid crystal display panel 1333. Therefore, it naturally becomes large. Another problem is that the input voltage of the fluorescent lamp is high. Usually, it is necessary to convert a DC voltage of about 5 V into an AC voltage of 100 to 200 V using an inverter and a booster coil. The total power efficiency of the inverter and booster coil is only about 80%, and power loss occurs here as well. Of course, the booster coil is large and requires a considerable volume. As an example, in a module size (product name UFU07F852) in which a flat fluorescent lamp for a 0.7-inch liquid crystal display panel manufactured by Ushio Inc. and a boosting coil are combined, the width is 22.7 mm, the height is 22.8 mm, and the depth is 11.3 mm. Yes, and it is heavy because it is made of glass. In addition, unnecessary radiation is large due to the use of a high AC voltage, which causes a beat failure in a display image of the liquid crystal display panel. Further, there is a problem that the fluorescent tube (the cold cathode type) does not turn on in a dark state and does not turn on when the temperature is low. Further, heat generation is large, and the liquid crystal display panel 1333 is likely to be adversely affected.
[0013]
It is an object of the present invention to provide a low power consumption liquid crystal display device and a viewfinder using the same.
[0014]
[Means for Solving the Problems]
A first invention provides a liquid crystal display panel,
Lighting means having a left-eye light-emitting element and a right-eye light-emitting element for illuminating the liquid crystal display panel,
Signal processing means for displaying an image for the left eye and an image for the right eye on the liquid crystal display panel,
Lighting control means for controlling on and off of the light emitting element for the left eye and the light emitting element for the right eye of the lighting means,
The signal processing means, on the liquid crystal display panel, sequentially displays the image for the left eye from one end of the screen, after displaying the image for the left eye, the image for the left eye from one end of the screen Delete or display a black image,
The signal processing means, on the liquid crystal display panel, sequentially display the image for the right eye from one end of the screen, after displaying the image for the right eye, the image for the right eye from one end of the screen Delete or display a black image,
The lighting control means turns on and off the light emitting element for the left eye in synchronization with the display of the image for the left eye,
The lighting control unit turns on and off the light emitting element for the right eye in synchronization with the display of the image for the right eye.,
The distance between the light-emitting element for the left eye and the light-emitting element for the right eye changes according to the distance between the liquid crystal display panel and the observer in the direction of incidence of the principal ray illuminating the liquid crystal display panel. Is adjustable asA liquid crystal display device characterized in that:
[0015]
A second invention is the liquid crystal display device according to the first invention, characterized in that the signal processing means causes the liquid crystal display device to hold signals having different polarities for each pixel row.
[0016]
A third aspect of the present invention is the liquid crystal display device according to the first aspect of the invention, wherein the illumination control means can change an incident direction of a principal ray for illuminating the liquid crystal display panel.
[0017]
A fourth aspect of the present invention is the liquid crystal according to any one of the first to third aspects, wherein the light emitting element for the left eye and the light emitting element for the right eye generate white light by the action of a phosphor. A display device.
[0018]
The fifth invention is a liquid crystal display device according to any one of the first to third inventions,
A viewfinder, comprising: a magnifying lens that magnifies a display image of the liquid crystal display device so as to be seen by an observer.
[0019]
Related to the present inventionThe invention provides a light emitting device,
Optical path separating means for separating light emitted by the light emitting element into a first optical path and a second optical path;
A liquid crystal display panel,
A light bending array in which a plurality of light bending means arranged on the light incident side of the liquid crystal display panel are provided,
In a liquid crystal display panel, a first pixel and a second pixel are arranged in a matrix.
One of the light bending means is arranged so as to correspond to the first pixel and the second pixel;
The light path separating means, the light of the first light path and the light of the second light path enter the light bending means at different angles,
The light is bent by the light bending means, and the light of the first optical path is configured to be incident on the first pixel, and the light of the second optical path is configured to be incident on the second pixel. A liquid crystal display device characterized in that:
[0020]
Related to the present inventionThe invention provides a first light emitting element,
A second light emitting element;
A liquid crystal display panel in which a first pixel and a second pixel are arranged in a matrix,
A lens disposed between the liquid crystal display panel and the light emitting element;
A splitter arranged on the light emission side of the liquid crystal display panel,
The splitter has a first passage area and a second passage area,
The first passage area substantially passes light emitted from the first light emitting element and passing through the first pixel in a first direction, and emitted from the second light emitting element to the first light emitting element. Light passing through the pixel is substantially blocked in a first direction,
The second passage area substantially passes light emitted from the second light emitting element and passing through the second pixel in a second direction, and emitted from the first light emitting element to the second light emitting element. A liquid crystal display device characterized in that light passing through a pixel is substantially blocked in a second direction.
[0021]
Related to the present inventionThe invention provides a light emitting device,
A liquid crystal display panel in which pixels are arranged in a matrix,
A first light bending array in which a plurality of first light bending means disposed on the light incident side of the liquid crystal display panel;
A second light bending array in which a plurality of second light bending means disposed on the light emission side of the liquid crystal display panel are provided,
The liquid crystal display device is characterized in that the first light bending means and the second light bending means correspond substantially one to one.
[0022]
Related to the present inventionThe invention provides a light emitting device,
A liquid crystal display panel in which a first pixel and a second pixel are arranged in a matrix,
Prism means arranged between the light emitting element and the liquid crystal display panel, wherein first and second slopes are alternately formed;
The light emitted from the first slope is arranged so as to be substantially incident on the first pixel, and the light emitted from the second slope is arranged so as to be substantially incident on the second pixel. A liquid crystal display device characterized by the following.
[0023]
Related to the present inventionThe invention provides a light emitting device,
A liquid crystal display panel in which pixels are arranged in a matrix,
A light bending array in which a plurality of light bending means are arranged between the light emitting element and the liquid crystal display panel,
Comprising first and second light emitting portions disposed between the light emitting element and the light bending means,
The liquid crystal display device, wherein the first and second light emitting portions correspond to the one light bending means.
[0025]
BookA driving method of a light emitting element according to a technique related to the present invention is a driving method of a lamp in which a filament that emits thermoelectrons and an anode are coated with a phosphor film on an inner surface of a case.
[0026]
The driving method according to the technology related to the present invention is to light a lamp by applying a voltage equal to or higher than a discharge starting voltage to a anode through a variable resistor, to reduce the voltage after lighting, and to reduce the resistance value of the variable resistor. Things. The current flowing to the anode is kept constant by reducing the voltage and the resistance value. Alternatively, a first voltage equal to or higher than a discharge starting voltage is applied via a first resistor, and after lighting, a switch lowers a second voltage lower than the first voltage to the second resistor to an anode. If the resistance value of the second resistor is smaller than the resistance value of the first resistor, the current value flowing to the anode by the first voltage after lighting and the current value flowing to the anode when switching to the second voltage are performed. Can be made substantially the same.
[0027]
In the driving method according to the technology related to the present invention, the lamp is lit by superimposing a pulse-like signal on the anode in a state where a third voltage lower than the discharge start voltage is applied to the anode, and setting the anode to the discharge start voltage or higher. It is to let.
[0028]
A driving method according to a technique related to the present invention is a method of supplying a current to a filament, applying a voltage to an anode to turn on a lamp, and then interrupting the supply of a current to the filament. By making the current flowing through the anode larger than a predetermined value, the filament is heated. The heating emits thermoelectrons from the filament, and the lighting of the lamp is maintained even when the current to the filament is stopped.
[0029]
A viewfinder of a technique related to the present invention uses a lamp having a filament and an anode as light generating means. And a liquid crystal display panel for modulating light emitted from the light condensing means. The anode of the lamp is planar, and the direction in which the filament and the anode are arranged is orthogonal as shown in FIG. 2 (b). A direct current is passed through the anode of the lamp. Preferably, a reflection film or the like is formed on the inner surface or outer surface of the lamp case and at a location where the light collecting means does not collect light. The reflection film or the like has a function of reflecting light emitted from the inside of the lamp case to the outside again into the lamp case.
[0030]
When the filament and the anode are perpendicular to each other, the light output intensity is maximized in a direction at an angle of 45 degrees. Therefore, an angle of 45 degrees is directed toward the liquid crystal display panel.
[0031]
On the other hand, since the lamp used in the viewfinder of the technology related to the present invention is DC-lit and the voltage applied to the anode is as low as 20 (V) or less, it is easily affected by static electricity. May disappear. Therefore, a transparent conductor film such as ITO is applied to the outer surface of the lamp, and a conductive wire or the like is sprinkled.
[0032]
Further, since mercury molecules in the lamp are converted into vapor to emit mercury molecules, it is necessary to increase the temperature of the mercury vapor in the case in order to obtain light emission luminance of a certain level or more. Conversely, when the outside air temperature decreases, the rise time of the light emission luminance of the lamp increases. As a countermeasure, the temperature of the lamp at the start of lighting is detected by a temperature sensor such as a thermistor, and the current value flowing through the anode during lighting is increased. Alternatively, the emission luminance of the lamp is measured after lighting, and feedback is applied to the amount of anode current.
[0033]
The view finder according to the technology related to the present invention includes an illumination optical system including a lamp and a parabolic mirror for illuminating the liquid crystal display panel. More preferably, a spherical mirror is arranged on the entire surface of the parabolic mirror. A parabolic mirror lamp is provided, and the parabolic mirror illuminates the liquid crystal display panel by condensing light emitted from the lamp and converting the light into parallel light. A light diffusion film is arranged between the lamp and the liquid crystal display panel. The reflecting surface of the parabolic mirror is embossed or composed of a plurality of micromirrors. A ring made of a resin (or glass or the like) that suppresses heat transfer is disposed at a place where the lamp and the parabolic mirror are close to each other, or a small gap is formed so as not to make contact. The lamp is covered with a rubber cap to which a diffusing agent such as Ti is attached.
[0034]
A viewfinder according to a technology related to the present invention includes a lamp, an illumination lens that collects light emitted from the lamp to convert the light into parallel light, and illuminates the liquid crystal display panel, and is disposed on a light exit surface of the liquid crystal display panel. Having an auxiliary lens. Preferably, a reflector is disposed on the rear surface of the lamp so that more light is illuminated on the liquid crystal display panel side. The liquid crystal display panel is sandwiched between an illumination lens and an auxiliary lens, and is perpendicular to the display surface of the principal ray liquid crystal display panel passing through the liquid crystal display panel. Preferably, the reflector is integrally formed on the rear surface of the resin, and the lamp is inserted after a hole is formed in the resin. At this time, the hole is made slightly larger than the diameter of the lamp so that when the lamp is inserted and fixed, a small space is kept between the resin hole and the lamp. An illumination lens or an auxiliary lens is attached to the liquid crystal display panel.
[0035]
A viewfinder of a technique related to the present invention is one in which an illumination optical system of a liquid crystal display panel is configured by a lamp and a Fresnel lens. Further, a diffusion sheet or the like is arranged between the Fresnel lens and the liquid crystal display panel. Preferably, the diffusion degree of the diffusion sheet is a ratio at which a groove of the Fresnel lens is visible when a viewer observes a display image on the liquid crystal display panel. The MTF (Modulation Transmission Function) is set to 20% or less. In addition, a polarizer is attached to a plane portion of the Fresnel lens, and the Fresnel lens can be rotated around the lens.
[0036]
A viewfinder according to a technique related to the present invention is configured so that at least one of a distance between a lamp and a condenser lens and a distance between a condenser lens and a liquid crystal display panel can be extended or contracted. When the viewfinder is not in use, it is contracted to shorten the overall length of the viewfinder, and when it is in use, it is extended, so that the light emission position of the lamp is exactly located at the focal position of the condenser lens.
[0037]
The viewfinder of the technology related to the present invention includes a condenser lens for introducing external light (sunlight or the like) into the viewfinder. Preferably, the condensing lens is formed of a Fresnel lens, and a light amount adjusting polarizing plate for adjusting the intensity of external light entering the viewfinder is preferably disposed. Normally, the polarization axis of the polarizing plate and the polarization axis of the polarizer of the TN liquid crystal display panel are made substantially coincident with each other, and when the external light is strong, the adjustment is performed by rotating the light amount adjusting polarizing plate.
[0038]
In the viewfinder of the technology related to the present invention, the magnifying lens is made of a flexible transparent resin. By pressing the peripheral portion of the lens made of transparent resin, the central portion becomes thicker and the focal length becomes shorter. When the pressure is removed, the central portion becomes thinner, the positive power becomes smaller, and the focal length becomes longer.
[0039]
The viewfinder of the technology related to the present invention is configured so that the optical axis at the center of the condenser lens and the central axis of the lamp can be changed. Preferably, the condenser lens is composed of a Fresnel lens, and a diffusion sheet is arranged on the light exit surface of the Fresnel lens. The viewfinder of the technology related to the present invention mainly uses two or more of the above-described viewfinders and converts an optical image formed by two or more display panels into a dichroic prism, a dichroic mirror, a half mirror, and a polarizing beam splitter (PBS). ) Etc. are combined into one optical path.
[0040]
A viewfinder according to a technology related to the present invention includes a lamp, a condensing unit that converts light emitted from the lamp into parallel light, a liquid crystal display panel, light reaching the left eye of the observer, and light reaching the right eye. And an image splitter for separating light from the light. Preferably, one lamp is arranged for each of the right eye and the left eye.
[0041]
The video camera of the technology related to the present invention mainly includes a viewfinder of the technology related to the present invention, and the viewfinder is attached to a predetermined position on the video camera, and the use position can be moved. I have. The camera further includes a push switch disposed on the main body of the video camera or the main body of the viewfinder and connected to a terminal of a filament of a lamp. Since the viewfinder is used, when the viewfinder is moved, the push switch is turned on, and current flows through the filament to preheat the lamp.
[0042]
It should be noted that a twisted nematic (TM) liquid crystal display panel, a polymer dispersed liquid crystal display panel, or the like is used as a light modulating means of a viewfinder or a display device according to the technology related to the present invention. In the case of using a polymer-dispersed liquid crystal, the thickness of the liquid crystal layer of the pixel that modulates red light is made larger than the thickness of the liquid crystal layer that modulates blue light. Alternatively, in addition, the average particle size of the liquid crystal droplets of the water-droplet liquid crystal or the average pore size of the polymer network is made larger for the pixel that modulates red light.
[0043]
The light emitting element of the technology related to the present invention is a constant current element. That is, when the lamp is turned on, the voltage between the anode electrode and the ground potential becomes a constant value regardless of the current flowing to the anode. The voltage at which this constant value is obtained is referred to as a sustaining voltage in the sense of a voltage for sustaining the discharge. However, even if the value is slightly lower than this value, the light is not suddenly turned off.
[0044]
On the other hand, in order to start discharge, a voltage higher than the discharge sustaining voltage is required. Usually about 5 (V) higher than the sustaining voltage. The voltage at which this discharge (light emission) is started is called a discharge start voltage. A current limiting resistor is interposed between the anode electrode and an anode terminal to which a voltage is applied. When the discharge start voltage is applied to the anode terminal, the discharge start voltage is applied to the anode electrode, and the discharge starts. Then, the potential of the anode electrode becomes the discharge sustaining voltage.
[0045]
That is, if the lamp is turned on, the discharge sustaining voltage may be applied to the anode electrode. The higher the voltage applied to the anode terminal, the greater the power lost by the current limiting resistor. This is the same even if the current limiting resistor is a constant current circuit.
[0046]
In a method of driving a lamp according to a technique related to the present invention, a voltage equal to or higher than a discharge starting voltage is applied to an anode via a resistance element, the lamp is turned on, and a steady current flows through the anode. Then, the voltage applied to the anode terminal is reduced while the resistance value of the resistance element is reduced while maintaining the value of the steady-state current. By controlling as follows, the resistance value of the resistance element ultimately becomes 0, and the voltage applied to the anode terminal can be the discharge sustaining voltage. Therefore, low power consumption can be achieved.
[0047]
The lamp of the technology related to the present invention is a constant current element, and starts lighting when a discharge start voltage is applied to the anode for about 10 μsec. In the driving method according to the technology related to the present invention, a discharge sustaining voltage is applied to an anode terminal in advance, and a voltage equal to or higher than a pulsed discharge starting voltage is applied to the anode terminal for about 10 μsec. The lamp is lit by the pulsed voltage, and when lit, the voltage at the anode terminal becomes the discharge sustaining voltage. Therefore, generation of the lamp can be maintained with low power.
[0048]
A driving method according to a technique related to the present invention is to cut off a current of a filament after lighting a lamp. In a hot cathode type lamp, a filament is heated, and the heating emits thermoelectrons from the filament. The thermoelectrons are heated by the potential of the anode and collide with mercury molecules to generate ultraviolet rays. Ultraviolet light is applied to the phosphor, the ultraviolet light is converted into visible light, and white light is emitted from the lamp. In other words, the filament needs to be heated in order to generate a lamp. However, when the current flowing into the anode is increased to a predetermined value or more, a part of the current acts on the filament, and the filament is heated. Alternatively, electrons are extracted from the filament by the potential of the anode electrode. Therefore, light emission continues even when the current of the filament is cut off.
[0049]
A DC positive voltage is applied to the anode electrode of the lamp, and a DC voltage (a ground potential at one terminal and a positive voltage at the other terminal) is applied to the filament. Thermoelectrons from the filament are attracted to the anode electrode. Therefore, as the potential difference between the filament and the anode electrode increases, thermionic electrons are accelerated, the collision with mercury molecules increases, and the amount of ultraviolet radiation increases.
[0050]
The viewfinder of the technique related to the present invention makes the filament and the anode electrode orthogonal to each other. Then, assuming that a positive (+) potential is applied to the anode electrode and that the ground potential is applied to the filament, the light emission luminance becomes highest in a direction exactly 45 degrees with respect to the filament forming direction. Therefore, the direction of 45 degrees at which the luminance is highest is directed to the direction of the liquid crystal display panel.
[0051]
The viewfinder of the technique related to the present invention illuminates the liquid crystal display panel by condensing the light of a small lamp by the condensing means. Since the light emitting area of the lamp can be reduced, low power consumption can be realized. The parabolic curve has a geometric property that the light emitted from the focal point is made parallel. In the viewfinder of the technology related to the present invention, the light emitting area of the lamp is arranged at the focal point of the parabolic mirror, and the light emitted from the lamp is made parallel by the parabolic mirror to illuminate the liquid crystal display panel. An observer looks at the display image on the liquid crystal display panel from the eye cap. When the lamp is close to the liquid crystal display panel, the lamp image may be seen. Therefore, a light diffusion (scattering) sheet is disposed between the liquid crystal display panel and the lamp as a countermeasure.
[0052]
The TN liquid crystal display panel can realize good contrast when vertical parallel light is incident. In the viewfinder, the diameter of the eyepiece that the observer looks into is small. This is for reducing the size of the viewfinder. Since the eyepiece is small, the principal ray emitted from the liquid crystal display panel needs to be narrowed (squeezed) toward the eyepiece. Therefore, only light that passes through the liquid crystal display panel is used as the light emitted from the lamp (or the surface light source), and the display contrast of the liquid crystal display panel is reduced.
[0053]
In the viewfinder of the technology related to the present invention, an auxiliary lens is arranged in front of the liquid crystal display panel, the light radiated from the lamp is collimated by the illumination lens, the parallel light passes through the liquid crystal display panel, and the auxiliary lens The chief ray is narrowed toward the eyepiece with. That is, the light incident on the liquid crystal display panel is telecentric. Therefore, light parallel to the normal to the display surface of the liquid crystal display panel can be made incident, and good display contrast can be obtained. If the auxiliary lens or the like is attached to the liquid crystal display panel, dust does not adhere to the display surface of the liquid crystal display panel.
[0054]
Overall length of just viewfinder for the illumination lens has a constant thickness using a convex lens made of plastic or glass is long. In the viewfinder of the technology related to the present invention, the illumination lens is constituted by a Fresnel lens. Since the Fresnel lens is a plate of 1-2 mm, the overall length can be shortened. However, when an observer views the display image on the liquid crystal display panel, the groove of the Fresnel lens may be seen. As a countermeasure, a light diffusion sheet is disposed between the Fresnel lens and the liquid crystal display panel.
[0055]
Further, the viewfinder of the technology related to the present invention is configured so that any one of between the illumination lens and the lamp, between the illumination lens and the liquid crystal display panel, or the like can be contracted or extended. Shrink the viewfinder when not in use. Therefore, the size can be reduced. When using the viewfinder, extend it so that the lamp comes to the focus of the illumination lens. Also, the observer is focused on the display surface of the liquid crystal display panel.
[0056]
When the video camera is used outdoors, external light such as sunlight is drawn into the viewfinder, and if it is possible to illuminate the liquid crystal display panel with this external line, there is no need to turn on the lamp. That is, power consumption can be reduced by turning off the lamp. Since sunlight has good parallelism, it can be well collected by a convex lens. This principle can be easily understood from the fact that sunlight can be condensed with a magnifying glass to burn black paper focused. The converged light can be restored to parallel light by using a convex lens. The viewfinder of the technology related to the present invention captures sunlight into a viewfinder with a condenser lens, and converts the captured light into parallel light with an illumination lens. The sunlight becomes parallel light with good narrow directivity (sharp directivity, although the degree is controversial) by the illumination lens.
[0057]
The viewfinder of the technology related to the present invention is one in which a magnifying lens is formed of a flexible resin. When the peripheral portion of the resin lens, which is a resin lens, is held down, the central portion swells and the focal length of the lens becomes short. Conversely, when the pressure at the peripheral portion is reduced, the lens returns to its original shape and the focal length of the lens becomes longer. In the conventional viewfinder, the observer adjusts the focal length of the liquid crystal display panel by adjusting the position of the eyepiece according to the eyesight of his or her own eye. The magnifying (eyepiece) lens is attached to the holder, and is configured to adjust the position of the holder. Therefore, a moving space for adjusting the position of the holder is required, and the total length of the viewfinder is reduced. In the viewfinder of the technology related to the present invention, the magnifying lens is made of resin, and therefore does not need to be moved back and forth. For this reason, since no holder is required, no moving space for position adjustment is required, and the total length of the viewfinder can be shortened.
[0058]
The viewfinder of the technology related to the present invention is configured so that the center optical axis of the condenser (illumination) lens and the center axis of the lamp can be changed. By changing the optical axis at the center of the condenser lens and the central axis of the lamp, the angle of the chief ray incident on the liquid crystal display panel can be changed.
[0059]
A viewfinder according to a technique related to the present invention combines images displayed on two or more liquid crystal display panels with a dichroic mirror or the like. The number of pixels of the cover image seen by the observer by combining the display images is the total number of pixels of the liquid crystal display panel × the number of panels used. Therefore, high-definition image display can be realized.
[0060]
A viewfinder according to a technique related to the present invention obliquely makes light emitted from two light sources (lamp) enter a liquid crystal display panel. The light from the first light source is configured to mainly enter the right eye of the observer, and the light from the second light source is configured to mainly enter the left eye of the observer. An image splitter for distributing light from the two light sources to the left and right eyes is disposed between the liquid crystal display panel and the viewer. The liquid crystal display panel displays an image for the left eye and an image for the right eye, the image on which the image for the left eye is displayed, the light from the first lamp, and the pixel on which the image for the right eye is displayed. Light from the second lamp. With the above configuration, the observer can see a stereoscopic image.
[0061]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0062]
FIG. 1 is a sectional view of a viewfinder according to a reference example relating to the present invention. However, it is schematically illustrated for ease of explanation. Some parts are partially enlarged or reduced, and some parts are omitted. The above also applies to other drawings.
[0063]
At one end of the viewfinder, a light source including a lamp 11, a parabolic mirror 12, a base substrate 14 for mounting the parabolic mirror 12, and the like is arranged. A diffusion (scattering) sheet 15 or a diffusion plate is disposed between the lamp 11 and the liquid crystal display panel 1333. Although either a diffusion plate or a diffusion sheet may be used, here, the description will be made as the diffusion sheet 15. The diffusion sheet 15 has a function of preventing an image of the lamp 11 from being seen when an observer (not shown) looks at a display image on the liquid crystal display panel 1333 via the magnifying (eyepiece) lens 1336. The light scattering characteristics of the diffusion sheet 15 may be low. This is simply to make the image of the lamp 11 difficult to see. Conversely, if the degree of scattering is high, the directivity of the light emitted from the lamp 11 is too wide, and the efficiency of using light from the lamp 11 is reduced. As an example of the diffusion sheet 15, there is a product number light-up series 100MX, 100SX, 100SH or 100S of Kimoto Corporation. Further, a diffusion plate of Tsutsuchu Plastic Co., Ltd. can also be used. It should be noted that the separated surface (embossed surface) 43 faces the liquid crystal display panel 1333 side as shown in FIG. An antireflection film is formed on the opposite surface. Otherwise, the light transmittance of the diffusion sheet 15 will be very poor. This configuration is important. In addition, a diffraction grating, a micro lens array, a cell hook lens array, or the like can be used as the diffusion plate. That is, the diffusion plate or the diffusion sheet 15 may be an optical low-pass filter.
[0064]
In FIG. 2, the parabolic mirror 12 is attached to the lamp 11 via a buffer member 26 (a specific shape is exemplified by a donut shape). Examples of the material of the buffer member 26 include Teflon, polypropylene resin, silicon rubber, polyester resin, acryl, polycarbonate, and the like. The heat from the lamp 11 is prevented from being transmitted to the parabolic mirror 15 and the lamp 11 is prevented from being transmitted. It has a function to buffer the impact on On the inner surface of the parabolic mirror 12, a reflection film made of aluminum (Al) is formed on the reflection surface 22. The light emitting area of the lamp 11 is located at the focal point of the parabolic mirror 12. Therefore, the light radiated from the lamp 11 is converted into parallel light (narrow directional light) by the parabolic mirror 12, passes through the diffusion sheet 15, and illuminates the liquid crystal display panel 1333. Although the reflecting surface 22 is formed or arranged on the inner surface of the parabolic mirror 12, if the parabolic mirror 12 is formed of a transparent material, a reflecting surface may be formed on the outer surface. For example, there is a case where a parabolic mirror is formed of an acrylic resin, and a metal thin film made of aluminum is formed on an inner surface or an outer surface thereof. When the parabolic mirror 12 is formed of a metal material, it is not necessary to newly form the reflection surface 22. This is because the parabolic mirror 12 itself made of a metal material can also serve as the reflection surface 22. Further, the parabolic mirror 12 may be formed by adding a titanium (Ti) powder to a polycarbonate resin. Titanium has the function of diffusing light. That is, a cloudy resin is used. In this case, it is not necessary to form the reflection surface 22. Although the directivity of the light radiated from the lamp 11 is poor, it cannot be practically used. FIG. 142 shows a characteristic example of the parabolic mirror 12. The effective diameter of the parabolic mirror 12 is larger than the diagonal length of the display area of the liquid crystal display panel 1333. This is for satisfactorily illuminating the liquid crystal display panel.
[0065]
Further, the inner surface of the parabolic mirror 12 may have a shape formed by combining a plurality of minute mirrors as shown in FIG. 3A, or an embossed shape as shown in FIG. 3B. With the configuration as shown in FIG. 3, uneven light emission due to the luminance distribution of the lamp 11 becomes less visible, and the liquid crystal display panel 1333 can be uniformly illuminated. This is particularly effective when the lamp 11 is a hot cathode type. This is because the lamp 11 has a large luminance distribution on the light emitting surface.
[0066]
As shown in FIG. 2, the parabolic mirror 12 is directly attached to and fixed to the socket 27 of the lamp 11 by a projection 30a. The socket 27 is fixed to the base substrate 14 with a protrusion 30b.
[0067]
The tip of the lamp 11 and the diffusion sheet 15 are separated by a certain distance. This is to prevent the heat of the lamp 11 from being conducted to the diffusion sheet 15 and deteriorating the diffusion sheet 15. Specifically, it is separated from 0.5 mm to about 2 mm. However, when the diffusion sheet 15 is plate-shaped and has good heat resistance, a depression may be formed in the center of the diffusion plate 15a as shown in FIG. With such a configuration, the lamp 11 can be axially aligned and fixed by the recess of the socket 27 and the diffusion plate 15a, so that the lamp 11 does not displace due to an impact or the like.
[0068]
Since the light emitted from the light emission area of the lamp 11 cannot be used to illuminate the liquid crystal display panel 1333 with the parabolic mirror 12, the light reflecting tube 32 is put on the lamp 11 as shown in FIG. The light reflecting tube 32 reflects the light emitted from the lamp 11 on its inner surface, returns it to the inner surface of the lamp 11 again, and is emitted from the effective light emitting area. Further, forming or disposing a reflective film on the bottom surface of the lamp 11 is directly connected to effective use of light. Thereby, the luminance rising characteristic and the starting characteristic of the lamp 11 are also improved.
[0069]
The lamp 11 has three terminals 16. One is an anode terminal 16c for applying a voltage to the anode electrode 25, and the other two are filament terminals 16a and 16b for supplying a current to the filament 24. Each terminal 16 passes through the inside of the socket 27 and is connected to the terminal 28. The terminal 28 is connected to the wiring of the base substrate 14 by solder 29. The components 17 (17a, 17b) of the drive circuit of the lamp 11 are mounted on the base substrate 14.
[0070]
Next, the lamp 11 will be described. The lamp case 21 of the lamp 11 is made of glass and is usually formed by processing a glass tube having a thickness of 0.21 to 0.5 mm. A filament 24 for emitting thermoelectrons and an anode electrode 25 for applying an electric field to the emitted thermoelectrons are arranged therein.
[0071]
The filament 24 includes barium, strontium, and calcium carbonate (BaCO 3).₃, SrCO₃, CaCO₃) And heated in vacuum to oxidize and form an activated oxide. The inner surface of the lamp case 21 is coated with a phosphor made of rare earth. In particular, a three-wavelength type phosphor is desirable. This is because the light transmittance matches the light transmittance of the color filter of the liquid crystal display panel, and the light use efficiency is improved. The color temperature of the emitted light is preferably from 6000K to 9000K. If the color temperature is 6000K or higher, the quality of the image becomes satisfactory. The higher the color temperature, the better the display quality, but the lower the display brightness of the lamp.
[0072]
The diameter of the lamp 11 is preferably 5 mm or less. This is because the volume of the lamp 11 is reduced, the luminance rising characteristics are accelerated, and the emission luminance is also increased. However, when the thickness is less than 2 mm, it becomes difficult to arrange the anode electrode 25 inside the lamp 11 and the discharge starting voltage increases.
[0073]
The anode electrode 25 has a ring shape and applies an electric field to thermoelectrons. Further, at the time of manufacture, mercury is penetrated or applied to the ring, and after the anode electrode 25 is disposed on the lamp case 21, it is also used to generate mercury vapor in the lamp case 21 by irradiating microwaves.
[0074]
Inside the lamp case 21, argon gas, krypton gas, neon gas and the like are sealed together with mercury vapor. Xenon gas can also be used. Xenon gas is preferred because it has low temperature dependence. However, the startability is deteriorated by using only xenon gas. Therefore, it is preferable to mix a small amount of neon gas with xenon gas. The luminous efficiency is high when the argon gas is 98% or more. However, the change in luminance with temperature is slightly large.
[0075]
The anode electrode 25 has a planar shape as shown in FIGS. Examples of the shape of the anode electrode 25 include a donut shape in (c), a plate shape in (d), and a shape in which a hole (a bulge or a concave portion) is formed in the center of (e). You. The planar shape of the anode electrode 25 means that it is not a cube, and this is applicable if the anode electrode 25 is planar as shown in FIGS.
[0076]
A direct current (DC) voltage in the range of 2.0 (V) to 6.0 (V) is applied to the two terminals (16a, 16b) of the filament 24. The voltage applied to the filament 24 is preferably in the range of 2.5 to 4.5 (V). Within this range, the generated luminance of the lamp 11 is high even if the input power is the same. This is because the surface area of the filament 24 increases. The filament 24 is heated by the applied voltage, and thermoelectrons are emitted from the oxide on the surface of the filament 24. A direct current (DC) voltage of 9 (V) or more is applied to the terminal 16c of the anode electrode 25. Although the voltage applied to the anode electrode 25 is DC, the voltage applied to the filament 24 may be AC.
[0077]
Electrons emitted from the filament 24 are accelerated by a voltage applied to the anode electrode 25, and thermal electrons collide with mercury molecules. Ultraviolet rays are generated by the collision, and the ultraviolet rays are radiated to the phosphor 23 to generate visible light.
[0078]
Anode voltage V during discharge (light emission)_a(Hereinafter, referred to as a discharge sustaining voltage) is 9.5 (V) to 11.5 (V). However, in order to start discharge (light emission), a voltage of 15.0 (V) or more (hereinafter, referred to as a discharge start voltage) is required. The discharge starting voltage increases as the diameter of the lamp 11 decreases.
[0079]
Ultraviolet rays are generated in the lamp case 21 by collision of thermionic molecules with thermionic electrons. The ultraviolet light generated is 254 nm. However, ultraviolet light having a wavelength of 185 nm is also generated in part. It is not preferable to use the 185 nm ultraviolet ray because it has a large energy and if a barium / magnesium-based phosphor is used, particularly the blue phosphor is greatly damaged and the color temperature changes. Note that one end of the lamp 11 is sealed with a bead-shaped sealing member 20.
[0080]
Note that a reflective film (reflective surface 22) made of aluminum (Al) may be formed inside the lamp case 21. The reflection film reflects the ultraviolet light in the case 21, and the reflected ultraviolet light is applied to the phosphor 23 on the front surface. Therefore, the light emission luminance in the effective light emission region is increased. By forming a film that reflects ultraviolet light on the inner surface as described above, light use efficiency can be improved.
[0081]
FIG. 2B is a sectional view of the lamp 11. The anode electrode 25 and the filament 24 are arranged substantially orthogonally. That is, the plane portion of the anode electrode 25 is orthogonal to the longitudinal direction of the filament 24.
[0082]
In FIG. 2, reference numeral 12 denotes a parabolic mirror, but is not limited to this. For example, as shown in FIG. 5A, a combination of a parabolic mirror and a spherical sphere may be used. In FIG. 5, light 51a emitted from the lamp 11 is reflected by the reflection surface 22 (region b in the figure) of the parabolic mirror 11 to be substantially parallel light, and illuminates the liquid crystal display panel 1333. If there is no spherical mirror (region a in the figure), the light ray 51c emitted from the lamp 11 will not be used again. However, if the generation area of the generation lamp 11 is positioned at the focal point of the spherical mirror, the light ray 51c is reflected by the area a of the reflection surface 22, becomes reflected light 51b, is again illuminated and scattered by the phosphor 23 of the lamp 11, and the light Are illuminated on the liquid crystal display panel 1333 as 51d. From the above, the light emission luminance of the lamp 11 can be improved by the spherical mirror, and the light use efficiency can be improved.
[0083]
In addition, it is preferable that the forming part of the spherical mirror is arranged at a position shown by oblique lines as shown in FIG. That is, the effective display area (image display section) of the liquid crystal display panel 1333 is irradiated with parallel light by the parabolic mirror 12, and the light radiated from the lamp 11 to the other area (shaded area) is transmitted to the lamp 11 by the spherical mirror. It is back.
[0084]
Note that the parabolic mirror, the spherical mirror, and the like do not necessarily mean a complete paraboloid or a spherical surface, but may have an aspherical shape. By experiment, the concave mirror is designed to be able to collect light better.
[0085]
The liquid crystal display panel 1333 is irradiated with substantially parallel light, but the substantially parallel light is light necessary for an observer to see a display image on the liquid crystal display panel 1333 well, and is strictly parallel light. Not something. For example, in the periphery of the display area of the liquid crystal display panel 1333, if the principal ray is not perpendicular, it is optically large, and in order to ensure sufficient directivity, the state of parallel light is considerably poor and the light spreads. The solid angle may be large. All of these are generally referred to as substantially parallel light for convenience.
[0086]
FIG. 6 shows the parabolic mirror 12 in which the light exit surface is raised and a reflection mirror 22a is arranged. The light 51 a emitted from the lamp 11 is reflected by the mirror 22 a and reflected by the mirror 22 b of the parabolic mirror 12 to illuminate the liquid crystal display panel 1333. Of course, the light 51b emitted from the tip of the lamp 11 directly illuminates the liquid crystal display panel 1333, and the light 51c is reflected once by the reflection surface 22b of the parabolic mirror 12 to illuminate the liquid crystal display panel 1333.
[0087]
At this time, in FIG. 7A, when the lamp 11 side is viewed from the diffusion sheet 15, a low luminance portion 71 may be generated on the outer peripheral portion of the lamp 11. This is because the buffer member 26 does not reflect light, so that a small amount of light enters the low-luminance section 71. In order to solve this, there is a method of covering with a rubber cap 72 as shown in FIG. A diffusing agent such as Ti is added to the rubber cap 72 to form a scatterer. The entire rubber cap 72 is illuminated by the rubber cap 72, and the low luminance portion shown in FIG.
[0088]
In addition to the rubber cap 72, silicon resin, polycarbonate, acrylic resin, epoxy resin, frosted glass, and the like can also be used. Preferably, a slight space is provided between the rubber cap 72 and the lamp 11. This configuration is shown in FIG. The space is held by the projection 73. The space has the effect of keeping the lamp 11 warm. This is because air has poor thermal conductivity. Due to the effect of the heat retention, the light emission brightness of the lamp 11 at a low temperature becomes good.
[0089]
There is also a method in which the lamp 11 is formed into a spherical shape without covering the rubber cap 72 as shown in FIG. Since the portion on which the phosphor 23 is applied becomes the light emitting surface, the low luminance portion 71 does not occur even if the buffer 26 is present.
[0090]
The larger the energy contained in the lamp 11 inside the lamp case 21, the higher the light emission luminance. Theoretically (ideally), the emission brightness is inversely proportional to the square of the inner diameter of the lamp. Therefore, in order to increase the light emission luminance, it is preferable that the tip of the lamp is thinner than the root as shown in FIG. In addition, it is preferable to form the reflection films 91a and 91b in a portion that cannot be used.
[0091]
It is effective to form or dispose a light-reflective metal thin film on the bottom surface of the lamp 11 and preferably on the side surface of the lamp 11 as shown in FIG. Examples of the metal thin film include an aluminum foil, a copper sheet, and a deposited aluminum film. The metal thin film (a thin film having conductivity and light reflectivity, for example, a carbon thin film may be applied) may be grounded to a fixed potential such as a ground terminal of the filament 24. With this configuration, the startability of the lamp 11 is improved. This is presumably because light generated by the lamp 11 is reflected by the conductive thin film, thereby increasing the energy density.
[0092]
As another method for improving the brightness, there is a configuration shown in FIG. FIG. 10A shows a lamp 11 covered with a light-collecting cap 101 having a concave emission surface, and FIG. 10B shows a prism-shaped (light-collecting prism 102) attached with an adhesive 103. is there. With this configuration, the amount of light that can be irradiated to the front can be increased. Of course, as shown in FIG. 10 (c), a configuration in which the lamp 11 is covered with a reflecting tube 105 made of metal or the like and the tip (front) portion is covered with a diffusion plate 106 is also favorable. By filling the transparent resin 104 between the reflecting tube 105 and the lamp 11, the entire area of the diffusion plate 106 has uniform brightness. It is also effective to cover the lamp 11 with a metal case (reflection cap 107) as shown in FIG.
[0093]
The lamp 11 is lit with a DC voltage and emits light. Further, the voltage applied to the anode electrode 25 is relatively low, that is, 20 (V) or less. Therefore, even when a voltage is applied to the lamp 11 charged with static electricity, the lamp 11 may not be turned on. In particular, if the lamp is turned on immediately after touching the surface of the lamp 11, the lamp may not light for a while. This is because human static electricity may be charged on the interface of the phosphor film 23 or the like. However, there is no practical problem since the lamp 11 is not directly touched with the hand in the viewfinder.
[0094]
As a countermeasure for preventing static electricity, there is a method of applying a transparent conductor film such as ITO to the outer surface of the lamp case 21 as shown in FIG. The ITO film 111 is grounded. Instead of the ITO film, there is also a method of slightly applying a conductive paste. There is also a method of applying carbon. In addition, there is a method of forming the antistatic film 112 as shown in FIG. Also, as shown in FIG. 12, a method of winding a conductive wire (enamel wire, carbon wire, etc.) around the outer periphery of the lamp 11 is effective. It is also effective to arrange a wire net or the like on the outer periphery of the lamp 11 as shown in FIG. By taking the above countermeasures, the lamp 11 can be reliably turned on without being charged.
[0095]
By using a nichrome wire as the conductor, the lamp 11 can be heated and the starting characteristics can be improved. For example, as shown in FIG. 43, when the switch 423 is turned on, a current is applied to the conductor. Immediately after the lamp 11 is heated by the application of the current and the voltage is applied to the anode electrode 25, steady light emission can be started well. This is particularly effective when the ambient temperature is low. Also effective as a measure against static electricity.
[0096]
As shown in FIG. 14, a method of grounding the anode electrode 25 via a high resistance (about 1 MΩ) is also effective as a countermeasure. The potential of the anode electrode 25 is stabilized, and charge is extremely reduced.
[0097]
Further, as shown in FIG. 15, when the parabolic mirror 12 is made of a conductor such as a metal which also serves as the reflecting surface 22, a good result can be obtained by grounding the parabolic mirror 12. Of course, a large amount of electric charge is generated, and when the lamp 11 is charged, it does not turn on. This is presumed to be because the electric field potential around the lamp 11 is stabilized.
[0098]
FIG. 44 shows a method in which the lamp 11 is used horizontally. The present invention is not limited to this, and the lamp 11 may be used vertically as shown in FIG. FIG. 44A shows a lamp case 401 covered with a transparent case having a concave emission surface, and FIG. 45B shows a prism-shaped one attached with an adhesive 301. With this configuration, the amount of light that can be irradiated to the front can be increased. Of course, as shown in FIG. 45 (c), a configuration in which a reflecting tube 302 made of metal or the like is covered on the lamp case 401 and a diffusion plate 293 is covered on the tip (front) portion is also favorable. By filling the transparent resin 291 between the reflecting cylinder 302 and the lamp case 401, the entire area of the diffusion plate 293 has uniform brightness. It is also effective to cover the lamp case 401 with a metal case 294 as shown in FIG.
[0099]
Next, a driving method of a light emitting element of a reference example related to the present invention will be described. Two voltages (currents) are required for lighting the light emitting element of the reference example related to the present invention. One is the filament voltage E_h  It is. The filament voltage is 1.5 (V) to 6.0 (V), and when the filament voltage is about 2 (V), the filament current flows about 40 (mA). The higher the filament voltage, the better. In particular, the range of 3.0 (V) to 5.0 (V) may be the same power amount. The other one is an anode voltage E applied to the anode electrode 25._aIt is. Anode voltage E_aAre a voltage for maintaining discharge (light emission) (discharge sustaining voltage Ec) and a voltage for starting discharge (light emission) (discharge start voltage Ec)._s). The discharge sustaining voltage Ec is a voltage between the anode electrode 25 and GND, and ranges from 9 (V) to 12 (V). However, the voltage tends to increase as the diameter of the lamp 11 decreases and the internal gas pressure increases. Discharge starting voltage E_sIs 15 (V) or more. Similarly, the smaller the diameter of the lamp 11 and the higher the internal gas pressure, the higher the voltage Es tends to be. In addition, the anode current I at the rated time_aIs 3 (mA) to 10 (mA).
[0100]
It is preferable that the power supply voltage used for the lamp 11 is lower because the power consumed by the lamp 11 decreases. Therefore, it is preferable that the voltage of the power supply is effectively applied to the anode electrode 25 to maintain a predetermined light emission luminance. Therefore, in the reference example relating to the present invention, as shown in FIG. 16, the lamp 11 is turned on and the light emitting state is maintained as follows.
[0101]
First, the voltage E is applied to the filament 24 before the voltage is applied to the anode electrode 25._hIs applied to heat the filament 24. If a voltage is applied to the anode electrode 25 without heating the filament 24, the role of reducing the oxide on the filament 24 becomes larger than usual, and the life of the lamp 11 is shortened. The voltage should be applied to the anode electrode 25 after at least 0.1 second or more has passed after the current of the filament 24 has passed.
[0102]
Next, the discharge start voltage E is supplied from the variable power supply 162._sAbove voltage E₁And the discharge starting voltage E is applied to the variable resistor 163._sAbove voltage E₁Is applied, the rated current I_aIs set to a value that flows. Note that the variable resistor 163 may be used in the sense of a variable current element, and may be configured by, for example, an FET, a transistor, or the like. Further, a thermistor or the like may be used. Voltage E₁Is applied, the lamp 11 starts emitting light. However, in this state, the voltage drop generated by the variable resistor 163 is large, and the power utilization is poor. Therefore, the timer circuit 161 changes the resistance value of the variable resistor 163 during a predetermined period (for example, one second after the lamp 11 is turned on), changes the voltage output from the variable power supply 162, and changes the anode discharge maintaining voltage E_cLower to about +0.5 (V).
[0103]
At this time, the current flowing through the variable resistor 163 has a predetermined value I_aTo maintain. Finally, the voltage drop at the variable resistor 163 is set to about 0.5 (V), and the anode electrode 25 has an anode sustaining voltage E_cIs applied. The predetermined time is set by microcomputer control of ON and OFF of the input switch SW of the timer circuit 161. Until the light emission of the lamp 11 becomes stable, the discharge sustaining voltage Ec changes. Therefore, the timer circuit 161 is operated after a sufficient time has elapsed.
[0104]
As another driving method, as shown in FIG._sAbove voltage E₁And a sustaining voltage E_cAbove voltage E₂There is a method in which the lamp 11 is turned on using two power supplies that generate the following. Hereinafter, the driving method shown in FIG. 17 will be described.
[0105]
Current limiting resistor R₁Is the power supply E₁Is applied to the anode electrode 25 when the predetermined current I is applied._aThrough which the current limiting resistor R₂Is the power supply E₂Is applied to the anode electrode 25 when the predetermined current I is applied._aIs to flow. First, the voltage E is applied to the filament 24._hIs applied to cause a current to flow through the filament 24. At this time, it is preferable that both the analog switches 172a and 172b be open. Next, the analog switch SW₁Is turned on (or off), and the voltage E is applied to the anode electrode 25.₁Is applied. Therefore, the lamp 11 starts discharging (light emission). Next, after a predetermined time, the switch SW is closed by the microcomputer, the logical output of the timer circuit 161 is inverted, and the analog switch SW is turned off.₂Is turned on, the analog switch SW is opened. Analog switch SW₂Is turned on, the anode electrode 25 has a voltage E₂Is applied, and the discharge state is maintained.
[0106]
16 and 17 show a case where the lamp 11 is turned on by applying a steady state voltage to the anode electrode 25, but FIG. 20 shows that a pulse or step-like voltage higher than the discharge starting voltage is applied to the anode electrode 25. The lamp 11 is turned on by applying the voltage. First, when the ON signal 2 is applied to the DCDC converter 201b, the filament voltage E is output from the voltage output terminal of the DCDC converter 201b._hIs output. Specifically, E_hIs around 2 to 3 (V). The current is a direct current of about 40 (mA). When the filament current flows through the filament 24, the oxide on the filament 24 is heated, and thermoelectrons are emitted.
[0107]
Next, the ON signal 1 is also applied to the DCDC converter 201a, and the discharge sustaining voltage E is output from the voltage output terminal._aIs output. Discharge sustaining voltage E_aIs specifically 9 (V) to 13 (V). VR is a volume for adjusting the current flowing into the anode electrode 25 during the discharge (light emission state) of the lamp 11. As the value of VR increases, the current flowing into the anode electrode 25 decreases, and the light emission luminance of the lamp 11 decreases. If the value of VR is reduced, the current flowing into the anode electrode 25 increases, and the light emission luminance of the lamp 11 increases. VR is also used to adjust individual variations of the lamp 11. This is because if the arrangement distance between the anode electrode 25 and the filament 24 is different, the brightness of each lamp 11 varies by about ± 20%.
[0108]
It is necessary that the value of VR can be adjusted from about 50Ω to about 300Ω. C₁Is an electrolytic capacitor, and Q₁Is an NPN transistor, Q₂Is a PNP transistor. Q when the output of the inverter 171 is L₂Turns on and the capacitor C₁B terminal is at the GND potential, and when the output of the inverter 171 is H, Q₁Turns on and the capacitor C₁The voltage E is_aIs applied. Electrolytic capacitor C₁Is determined by the time constant with the resistance value of VR. It is necessary to apply a voltage equal to or higher than the discharge starting voltage to the anode electrode 25 for at least 2 μsec. Preferably, the voltage needs to be applied for 10 μsec or more.
[0109]
The anode electrode 25 has a discharge sustaining voltage E_aIs applied first. Next, the output of the inverter 201 is first set to L level by a microcomputer or the like, and the capacitor C₁Is set to a voltage of GND + 0.6 (V). At this time, the capacitor C₁A terminal of E_aVoltage is applied. Next, the output of the inverter 171 is set to the H level. Then, the capacitor C₁Terminal b suddenly changes from GND + 0.6 (V) to E_a-0.6 (V). Therefore, the capacitor C₁E terminal is a_a+ (E_a-0.6) (V). If the voltage is equal to or higher than the discharge starting voltage for a period of 2 μs or longer, the lamp 11 is turned on. When the lamp 11 lights up, the capacitor C₁The electric charge charged in the terminal a of FIG. 1 flows into the anode electrode 25, and the terminal a_a−VR (resistance value) × anode current).
[0110]
To turn off the lamp 11, the output of the inverter 171 is changed to the L level in the lighting state. Then, the capacitor C₁Since the terminal b has GND + 0.6 (V), the terminal a changes in the same manner, and the voltage of the anode electrode 25 becomes considerably lower than the sustaining voltage, so that the lamp 11 is turned off. Note that the capacitor C₁, Transistor Q₁, Q₂This configuration is for applying a pulse-like voltage higher than the discharge starting voltage to the anode electrode 25, and it goes without saying that other configurations may be used.
[0111]
For example, an FET or the like can be used. Further, the voltage applied to the anode electrode 25 may be a voltage equal to or higher than the discharge starting voltage, and may be a pulse, a step, a distorted rectangle or a sine wave. Also, the voltage E from the battery 202 via the DCDC converter 201_a, E_hHowever, the output voltage from the battery 202 may be directly applied to the anode electrode 25 if the battery voltage is equal to or higher than the sustaining voltage.
[0112]
In order to adjust the light emission luminance of the lamp 11, there is a method of adjusting the resistance by VR, or a method of applying a pulse-like voltage to the anode electrode 25 as shown in FIG. When light enters the photodiode 181 in the light detection circuit 183, the output voltage of the operational amplifier 182 increases. The output voltage of the photodiode 181 increases when external light is strong. C and R of the light detection circuit 183 are integration circuits for reducing noise of the output from the photodiode 181. The limited number of CRs is 1/10 second or less.
[0113]
When the output voltage of the operational amplifier is high (at this time, the external light is strong, that is, when it is used outdoors or the like), the emission luminance of the lamp 11 is increased. Conversely, when the output voltage of the operational amplifier is low (at this time, the external light is weak, that is, when it is used indoors or the like), the luminance of the lamp 11 may be low. When the voltage input to the oscillation circuit 184 is high, the oscillation state becomes the state (2) (there are many parts where the voltage is high). Conversely, when the voltage input is low, the oscillation state becomes the state (1) (the voltage Are often low).
[0114]
It should be noted that the longer the voltage is applied, the longer the time period during which the voltage is applied to the anode electrode 25, and a high brightness display is performed as an effective value. The output of the oscillation circuit 184 is input to the amplifier 185, and the output of the amplifier 185 outputs a rectangular wave of a voltage E equal to or higher than the GND voltage and the discharge start voltage. The longer the period of the voltage E equal to or higher than the discharge start voltage, the higher the brightness of the lamp 11 is lit. The resistance R_aIs a current limiting resistor.
[0115]
In FIG. 16, while the resistance value of the variable resistor 163 changes, in FIG.₁, SW₂19, the pulsed voltage is applied in FIG. 19, and the emission luminance of the lamp 11 may change until the lamp is stably turned on. During this time, if the observer views the display image on the display panel 1333, he / she will feel uncomfortable. The viewfinder of the reference example related to the present invention solves this measure as shown in FIG. 19 below.
[0116]
First, a driving circuit of the liquid crystal display panel 1333 will be described. Reference numeral 191 denotes a video amplifier for amplifying a video signal to a predetermined value, 192 denotes a phase division circuit for generating positive and negative video signals, 193 denotes an output switching circuit for outputting an AC video signal whose polarity is inverted for each field, and 194 denotes A drive circuit control section for synchronizing and controlling the source drive circuit 195 and the gate drive circuit 196.
[0117]
First, the gain of the video signal is adjusted by the video amplifier 191 so that the video output amplitude corresponds to the electro-optical characteristics of the liquid crystal. Next, the gain-adjusted video signal enters the phase division circuit 192, and two video signals of positive polarity and negative polarity are generated. These two video signals enter the output switching circuit 193, and output a video signal whose polarity is inverted every field or one horizontal scanning period. The reason for inverting the polarity of the signal for each field in this way is to prevent the liquid crystal from deteriorating by applying an AC voltage.
[0118]
Next, the video signal from the output switching circuit 193 is input to the source drive circuit 195, and the source drive circuit 195 performs signal processing such as level shift and sample hold of the video signal according to a control signal from the drive circuit control unit 194. A predetermined voltage is output to the source signal line of the liquid crystal display panel 1333 in synchronization with the gate drive circuit 196.
[0119]
When an on-voltage is applied to the gate signal line, the TFT connected to the gate signal line is turned on, and applies the video signal output to the source signal line to the pixel electrode. When an off-voltage is applied to the gate signal line, the TFT is turned off, and the signal applied to the pixel voltage is held for one field.
[0120]
In the example of FIG. 16, the first stage (the variable power supply 162 supplies the discharge maintaining voltage E_cAt +0.5 (V)), the switch SW1 is connected to the ground (for example, the potential of the counter electrode 243 of the liquid crystal display panel 1333) (terminal b position). Next, in the second stage (after the variable power supply 162 outputs the sustaining voltage Ec + 0.5 (V)), the switch SW1 is switched to the terminal a, a video signal is applied to the amplifier 191, and an image is displayed on the liquid crystal display panel 1333. Is displayed.
[0121]
When the switch SW1 is at the terminal b, no image is displayed on the liquid crystal display panel 1333 (the image is controlled to display black). Even if the light emission luminance of the lamp 11 changes during black display, the change is hardly recognized by the observer. Note that the above-described black display means a non-video display state, and is a concept including a display state such as raster display and dark display in addition to black display.
[0122]
In the viewfinder of FIG. 1, the observer adjusts the position by moving the magnifying lens 1336 back and forth so that a virtual image of the display image on the liquid crystal display panel 1333 can be seen well. Therefore, the magnifying lens 1336 is attached to the attachment holder 1335. That is, focus adjustment is performed by moving the mounting holder 1335 back and forth. Therefore, the distance required for the mounting holder 1335 to move is required, and the total length of the viewfinder becomes longer by that much.
[0123]
With the configuration shown in FIG. 21, the mounting holder 1335 is not required. The magnifying lens 1336a is made of a flexible transparent material such as silicone resin. In the magnifying lens 1336a, the edge (the side surface of the lens, the fixed portion of the lens) is sandwiched by pressing means such as a iris diaphragm. The rainbow collecting aperture is attached to the outer housing 211, and the aperture of the rainbow collecting aperture can be changed by moving the aperture knob 212.
[0124]
When the hole of the rainbow diaphragm 213 is large as in FIG. 22A, the center thickness of the magnifying lens 1336a is small. Therefore, the focal point f of the magnifying lens 1336a₁Is long. On the other hand, when the hole is large as in the rainbow collecting aperture 1336b as shown in FIG. 22B, the center thickness of the magnifying lens 1336a is large. Therefore, the focal point f of the magnifying lens 1336a₂Becomes shorter. As described above, the focus of the lens 1336a can be changed by the aperture knob 212, and focus adjustment can be easily performed. Therefore, the mounting holder 1335 is not required.
[0125]
The magnifying lens 1336a can be made of natural rubber, synthetic rubber, or the like, in addition to the silicone resin described above, and a liquid crystal lens can be applied. The liquid crystal lens has liquid crystal interposed between two electrodes. By applying a voltage to the electrodes, the refractive index of the liquid crystal changes, and the focal length f of the liquid crystal lens can be changed. In this case, there is no need for a rainbow stop.
[0126]
As the liquid crystal display panel 1333, a TN liquid crystal display panel or an STN liquid crystal display panel is exemplified, and a ferroelectric liquid crystal display panel, an antiferroelectric liquid crystal display panel, a cholesteric liquid crystal display panel, or the like can also be used. Further, a display panel to which PLZT is applied can also be used. That is, any transmissive display panel can be employed. In addition, a polymer dispersed liquid crystal display panel can be used. The panel is a liquid crystal in a mode in which light is modulated by transmitting and scattering light, and has a very high light use efficiency because a polarizing plate is used.
[0127]
When a TN or STN liquid crystal display panel is used as the liquid crystal display panel 1333, the liquid crystal display panel is generally well-known and need not be described. However, in the case where a PD liquid crystal display panel is used as the liquid crystal display panel 1333, explanation is considered to be necessary, so that the explanation is given here.
[0128]
The operation of the PD liquid crystal display panel will be briefly described with reference to FIGS. FIGS. 24A and 24B are diagrams illustrating the operation of the PD liquid crystal display panel. In FIGS. 24A and 24B, a liquid crystal in the form of water droplets (hereinafter referred to as a liquid crystal in the form of water droplets 245) is dispersed in the polymer 246. A TFT (not shown) or the like is connected to the pixel electrode 244, and a voltage is applied to the pixel electrode 244 when the TFT is turned on or off, and the direction of liquid crystal alignment on the pixel electrode 244 is changed to modulate light. As shown in FIG. 24A, when no voltage is applied, each of the liquid crystal droplets 245 is oriented in an irregular direction. In this state, a difference in refractive index occurs between the polymer 246 and the liquid crystal 245, and the incident light is scattered.
[0129]
Here, as shown in FIG. 24B, when a voltage is applied to the pixel electrode 244, the directions of the molecules of the liquid crystal 245 are aligned. If the refractive index when the liquid crystal molecules are aligned in a certain direction is adjusted in advance to the refractive index of the polymer 246, incident light is emitted from the array substrate 242 without being scattered.
[0130]
Nematic liquid crystal, smectic liquid crystal, and cholesteric liquid crystal are preferable as the liquid crystal material used for the liquid crystal display panel such as the view finder of the reference example related to the present invention. It may also be a mixture that contains.
[0131]
Incidentally, among the liquid crystal materials described above, the extraordinary light refractive index n_eAnd ordinary refractive index n_oCyanobiphenyl-based nematic liquid crystal having a relatively large difference between them, or a fluorine-based or chloro-based nematic liquid crystal that is stable to changes over time is preferable. Most preferred.
[0132]
As the polymer matrix material, a transparent polymer is preferable. As the polymer, a photo-curable resin is used in view of easiness of the manufacturing process, separation from the liquid crystal phase, and the like. As a specific example, an ultraviolet curable acrylic resin is exemplified. In particular, a resin containing an acrylic monomer or acrylic oligomer which is polymerized and cured by irradiation with ultraviolet light is preferable. Above all, a photocurable acrylic resin having a fluorine group is preferable because a light modulation layer (liquid crystal layer) 248 having good scattering characteristics can be produced and a change with time hardly occurs.
[0133]
The liquid crystal material has an ordinary refractive index n.₀Is preferably 1.49 to 1.54, and above all, the ordinary refractive index n₀Is preferably 1.50 to 1.53. Further, it is preferable to use one having a refractive index difference Δn of 0.20 or more and 0.28 or less. n₀, Δn increase, heat resistance and light resistance deteriorate. n₀, Δn are small, the heat resistance and light resistance are improved, but the scattering characteristics are reduced and the display contrast is not sufficient.
[0134]
From the above, as a constituent material of the light modulation layer 248, the ordinary refractive index n₀It is preferable to use a chloro-type nematic liquid crystal having a ratio of 1.50 to 1.53 and Δn of 0.20 to 0.28, and to employ a photocurable acrylic resin having a fluorine group as a resin material.
[0135]
Examples of such a polymer-forming monomer include 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, neopentyl glycol acrylate, hexanediol diacrete, diethylene glycol diacrylate, tripropylene glycol diacrylate, polyethylene glycol diacrylate, and trimethylolpropane. Triacrylate, pentaerythritol acrylate and the like.
[0136]
Examples of the oligomer or prepolymer include polyester acrylate, epoxy acrylate, and polyurethane acrylate.
[0137]
Further, a polymerization initiator may be used in order to quickly carry out the polymerization. Examples of the polymerization initiator include 2-hydroxy-2-methyl-1-phenylpropan-1-one (“Darocur 1173” manufactured by Merck), 1- (4-Isopropylphenyl) -2-hydroxy-2-methylpropan-1-one (“Darocur 1116” manufactured by Merck), 1-vidroxycyclohexylphenyl ketone (“Irgacure 184” manufactured by Ciba-Gaiky), benzyl methyl ketal ( “Irgacure 651” manufactured by Ciba-Geigy) and the like. In addition, a chain transfer agent, a photosensitizer, a dye, a cross-linking agent and the like can be appropriately used as optional components.
[0138]
The refractive index n when the resin material is cured_pAnd the ordinary refractive index n of the liquid crystal_oShould be approximately the same as When an electric field is applied to the liquid crystal layer 248, the liquid crystal molecules are aligned in one direction, and the refractive index of the liquid crystal layer 248 becomes n._oIt becomes. Therefore, the refractive index n of the resin_pAnd the liquid crystal layer 248 is in a light transmitting state. Refractive index n_pAnd n_oIs large, the liquid crystal layer 248 is not completely in the transparent state even when a voltage is applied to the liquid crystal layer 248, and the display luminance is reduced. Refractive index n_pAnd n_oIs preferably within 0.1, more preferably within 0.05.
[0139]
Although the proportion of the liquid crystal material in the PD liquid crystal layer is not specified here, it is generally about 60% to 95% by weight, preferably about 70% to 90% by weight. If it is less than 50% by weight, the amount of liquid crystal droplets is small, and the scattering effect is poor. When the content is 90% by weight or more, the polymer and the liquid crystal tend to be phase-separated into upper and lower layers, the ratio of the interface is reduced, and the scattering characteristics are reduced. The structure of the polymer-dispersed liquid crystal layer changes depending on the liquid crystal fraction. At about 50% by weight or less, liquid crystal droplets exist as independent droplets, and at 50% by weight or more, a continuous layer is formed in which the polymer and the liquid crystal are intertwined. .
[0140]
It is preferable that the average particle diameter of the water-drop liquid crystal 245 or the average pore diameter of the polymer network be 0.5 μm or more and 2.0 μm or less. Among them, the thickness is preferably 0.6 μm or more and 1.5 μm or less. When the light modulated by the PD liquid crystal display panel has a short wavelength (for example, B light), the light is small, and when the light is long wavelength (for example, R light), the light is increased. If the average particle diameter of the water-drop liquid crystal 245 or the average pore diameter of the polymer network is large, the voltage to make the liquid crystal in the transmission state is low, but the scattering characteristics are low. When it is small, the scattering characteristics are improved, but the voltage required for the transmission state is high.
[0141]
The average particle size or average pore size on the pixel that modulates red light is 0.8 μm or more and 1.5 μm or less, and the average particle size or average pore size on the pixel that modulates blue light is 0.5 μm or more and 1.0 μm or less. . And at least the particle or pore size on the pixel that modulates red light should be larger than the pixel that modulates blue light. This is for improving the scattering characteristics of each pixel.
[0142]
The polymer-dispersed liquid crystal of the reference example related to the present invention includes a water-drop liquid crystal 245 (see FIG. 24) in which the liquid crystal is dispersed in a resin in a water-drop shape, a sponge-like (polymer network) resin, and a sponge-like liquid. This corresponds to, for example, a liquid crystal filled between resins. The polymer-dispersed liquid crystal also includes a liquid crystal and a resin in which a liquid crystal and a resin are alternately stacked to form a layer (JP-A-6-208126 and JP-A-6-22085). Further, the polymer-dispersed liquid crystal includes a liquid crystal in which the liquid crystal is sealed in a capsule-like storage medium and the space between the capsules is filled with a resin (Japanese Patent Publication No. 3-52843). Further, the polymer-dispersed liquid crystal includes a liquid crystal or a resin (polymer 246) containing a dichroic or polychromatic dye.
[0143]
The thickness of the liquid crystal layer 248 is preferably in the range of 5 to 20 μm, and more preferably in the range of 8 to 15 μm. When the film thickness is small, the scattering characteristics are poor and contrast cannot be obtained. On the contrary, when the film thickness is large, high voltage driving must be performed, and a gate drive circuit (see FIG. It is difficult to design a source drive circuit (not shown) for applying a video signal to a source signal line (not shown).
[0144]
For controlling the thickness of the liquid crystal layer 248, black glass beads or black glass fibers, or black resin beads or black resin fibers are used. In particular, black glass beads or black glass fibers are preferable because they have a very high light-absorbing property and are hard, so that a small number of particles are scattered on the liquid crystal layer 248. It is effective to form an insulating film on at least one of the pixel electrode and the counter electrode.
[0145]
As the insulating film, an alignment film such as polyimide used for a TN liquid crystal display panel or the like, an organic material such as polyvinyl alcohol (PVA), SiO 2₂And the like. Preferably, an organic substance such as polyimide is preferable from the viewpoint of adhesion and the like. The use of polyimide as the insulating film is particularly useful.
[0146]
In PD liquid crystal display panels, it is also important to prevent electromagnetic coupling between signal lines and pixel electrodes. An alternating current is constantly applied to the source signal line 249 in FIG. Accordingly, lines of electric force are generated between the pixel electrode 244 and the source signal line 249 in FIG. 23, and the liquid crystal molecules are aligned on the lines of electric force, so that “light loss” occurs from the periphery of the pixel electrode 244 and the like.
[0147]
As a countermeasure against the "light leakage", the source signal line 249, the gate signal line, and the vicinity of the signal line are shielded with a material having a lower dielectric constant than the liquid crystal layer 248 (hereinafter, referred to as a low dielectric material). Low dielectric material is SiO₂, SiNx, and the like, an organic material such as a polymer of the liquid crystal layer 248, a resist, and PVA.
[0148]
Also, it must be remembered that there is also a configuration using a PD liquid crystal display panel and a polarizing plate. By disposing a polarizing plate on at least one of the light entrance side and the light exit side of the PD liquid crystal display panel, the display contrast can be greatly improved.
[0149]
In FIG. 23A, the average particle diameter of the liquid droplets 248 or the average pore diameter of the polymer network is changed according to the color of the color filter 230. At least that of the red pixel is larger than that of the blue pixel. As a method of changing the average particle diameter, a PD liquid crystal display panel corresponding to red (R), green (G), and blue (B) pixels and having a different amount of transmitted ultraviolet light for each of R, G, and B is used. At the time of manufacturing, the liquid crystal layer 248 may be arranged on the panel surface, and the panel may be irradiated with ultraviolet rays through the mask to polymerize the resin of the liquid crystal layer 248. The location where the irradiation intensity of the ultraviolet light is weak has a large average particle diameter and the like, and the location where the intensity is strong is small.
[0150]
As shown in FIG. 23B, it is also important to change the thickness of the liquid crystal layer 248 for each of the R, G, and B pixels. The liquid crystal layer 248 can be formed by forming transparent resins 231a and 231b as shown in the figure. Examples of the transparent resin 231 include gelatin, polyimide, UV resin, and epoxy resin. The transparent resin 231 may be formed on the counter electrode 243 as shown in the figure, or the counter electrode 243 may be formed on the transparent resin 231 on the contrary. Further, it may be formed directly on the pixel electrode 244.
[0151]
As shown in FIG. 23B, the thickness of the liquid crystal layer 248 of the pixel corresponding to the R color is set to be larger than the thickness of the liquid crystal layer 248 of the pixel corresponding to the B color. This is because it is necessary to increase the size such as the average particle diameter for the R light. The average particle diameter and the like may be considered to be substantially proportional to the wavelength of the light to be modulated. On the other hand, when the average particle diameter increases, the voltage required for the light transmission state decreases for the same liquid crystal film thickness. It is preferable that the film thickness of the R light liquid crystal layer has a difference of 1 μm or more from that of the B light. Alternatively, the R light liquid crystal layer is preferably formed to be 1/10 or more thicker than the B light.
[0152]
In FIG. 23B, the color filter 230 is not shown. Even without a color filter, a microlens array 1224 is attached to the liquid crystal display panel 1333 as shown in FIG. 122 (b), and the same color light from the light source 1221 is separated into R, G, and B light by a dichroic mirror, and each pixel is separated. What is necessary is just to make it enter into 244a, 244b, 244c. That is, one microlens is assigned to three pixels.
[0153]
FIG. 2 shows a configuration in which the tip of the lamp 11 is directed toward the liquid crystal display panel 1333. However, in this configuration, it is necessary to ensure the length of the lamp 11, so that the entire length of the viewfinder becomes long. FIG. 25 solves this problem. The side surface of the lamp 11 is arranged to face the liquid crystal display panel 1333. FIG. 26 is a sectional view taken along line AA 'in FIG. The lamp 11 is attached to the base substrate 14 via a socket 27. The reflecting surface 22a has a two-dimensional parabolic shape, and the reflecting surface 22b has a three-dimensional parabolic shape.
[0154]
The reflection surface 22b collects light from the tip of the lamp 11, converts the light into parallel light, and illuminates the liquid crystal display panel 1333. The light emitting portion of the lamp 11 is located at a substantially focal position of the reflection surface 22b. The reflection surface 22a is made substantially parallel to the side surface of the lamp 11. Further, a reflection film 91 is formed on the back surface of the lamp 11 (where the lamp 11 and the reflection surface 22a face each other) with the side surface of the lamp 11 as the center. If there is no reflective film 91, a light ray 51a is emitted.
[0155]
The light ray 51a hits the reflecting surface 22a and becomes reflected light 51c. However, 51c only hits the lamp 11 and hardly becomes light for illuminating the liquid crystal display panel. When the reflective film 91 is provided, the light generated by the lamp 11 hits the reflective film 91 and becomes a reflected light beam 51b, and the front surface of the lamp is made bright, and the liquid crystal display panel 1333 is made bright.
[0156]
FIG. 27 is a configuration diagram of a viewfinder that employs the illumination optical system in which the lamp 11 of FIG. 26 is arranged. Compared with FIG. 1, the total length of the viewfinder can be reduced.
[0157]
Hereinafter, the configuration in which the lamps 11 are arranged as shown in FIG. 26 is called a lamp vertical arrangement or a lamp vertical arrangement illumination system, and the configuration in which the lamps 11 are arranged as shown in FIG. 2 is called a lamp horizontal arrangement or a lamp horizontal arrangement illumination system.
[0158]
In the configuration of the lamp vertical arrangement, it is necessary to consider the arrangement direction of the filament 24 of the lamp 11. Hereinafter, the reason and the configuration will be sequentially described.
FIG. 28B shows an arrangement of the filament 24 and the anode electrode 25. It is assumed that the anode electrode 25 has a planar shape. The longitudinal direction of the filament 24 and the longitudinal direction of the anode electrode 25 are arranged so as to be orthogonal to each other.
[0159]
FIG. 28A shows a result of measuring the luminance distribution in the circumferential direction of the lamp case 21 in the arrangement state of the filament 24 and the anode electrode 25 as shown in FIG. 28B. In addition, it is assumed that the reflection film 91 and the like are not formed on the lamp case 21. As is clear from FIG. 28A, the brightness becomes highest at 45 degrees (DEG.) And 315 degrees. Further, the luminance becomes lowest at 0 degrees and 180 degrees.
[0160]
The thermoelectrons emitted from the filament 24 are accelerated by the anode voltage of the anode electrode 25. Therefore, the greater the potential difference between the filament 24 and the anode electrode 25, the greater the acceleration and the greater the amount of generated ultraviolet light. Since point A of the filament 24 shown in FIG. 28B is GND, the potential difference between the anode electrodes 25 is large. Therefore, as shown in FIG. 28A, the light emission luminance becomes highest at the angle between the longitudinal direction (0-180 degrees) of the filament 24 and the central portion in the longitudinal direction (90-270 degrees) of the anode electrode 25. When the display panel 1333 and the like are illuminated with the light-emitting element, it is more advantageous to direct the surface with the highest luminance to the display panel 1333. Therefore, the angle range of ± 30 degrees around the GND side of the filament 24 may be directed to the liquid crystal display panel 1333.
[0161]
In the case of the vertical arrangement of the lamp, in order to maximize the light emitted from one side surface of the lamp 11, it is preferable to form a reflection film 91 on one internal surface of the lamp case 21, as shown in FIG. Alternatively, as shown in FIG. 29 (b), it may be formed on one outer surface of the lamp case 21. The portion where the reflection film 91 is formed is made of SiO 2 to prevent oxidation.₂, SiN_xIt is preferable to form a protective film 291 such as
[0162]
In FIG. 28B, the generation amount of ultraviolet rays is small in the directions A and B, and the generation amount of ultraviolet rays is large in the directions C and D. Further, the acceleration rate of the thermoelectrons is determined by the distance between the anode electrode 25 and the filament 24 and the potential difference. Therefore, if the variation in the position between the anode electrode 25 and the filament 24 is large, the variation in the emission luminance of each lamp 11 also becomes large. In the configuration in which the filament 24 and the anode 25 are arranged at the tip of the terminal 16 as shown in FIG. 29, the position of the filament 24 and the anode electrode 25 tends to vary.
[0163]
FIG. 30 shows a structure for solving the above problem. The filament 24 and the anode electrode 25 are fixed to one mounting glass 301. Therefore, the filament 24 and the anode electrode 25 can be completely fixed, and the positional relationship can be made with high precision. Therefore, the variation in light emission luminance of each lamp 11 is small, and the production yield can be increased. The longitudinal direction of the filament 24 is defined as the longitudinal direction of the lamp case 21. Therefore, it is possible to increase the amount of ultraviolet irradiation on the surface A, and to improve the light emission luminance of the surface A.
[0164]
The point A of the filament 24 is GND, and the potential difference from the anode electrode 25 is the largest. Therefore, the anode electrode 25 should be arranged close to the point A of the filament 24. In addition, the anode electrode 25 increases the reflectance. This is because the anode electrode 25 plays a role of a reflection film. Further, the shadow of the filament 24 may appear on the surface A, but this can be reduced by appropriately adjusting the film thickness of the phosphor 23 and the like.
[0165]
As shown in FIG. 31A, the light-emitting element of the reference example related to the present invention emits the A-plane (light-emitting region 311) with the highest luminance. This is because increasing the luminance of some regions is suitable for a viewfinder of a reference example related to the present invention described later. In FIG. 30, the longitudinal direction of the filament 24 is arranged in the longitudinal direction of the lamp case 21. However, the present invention is not limited to this, and the filament 24 may be arranged in the radial direction of the lamp case 21. In this case, the light emitting region (A surface) 311b is as shown in FIG.
[0166]
The lamp 11 of the reference example relating to the present invention is used with the A side in FIG. 30 facing the front. Therefore, when used in a viewfinder or the like, it is necessary to consider the direction of the filament 24. Therefore, when the lamp 11 is manufactured, it is preferable to draw a marker 312 made of a black line or the like on the outer surface of the lamp case 21 as shown in FIG. A recess 313 (see FIG. 31 (c)) is provided in the lower portion of the lamp case 21.
[0167]
It is also effective to form a transparent projection 314 (triangular prism, triangular cone, etc.) in the light emitting region 311 as shown in FIG. The transparent protrusions 314 sharpen the directivity of light and can increase the brightness, so that the light utilization rate can be improved.
[0168]
The diffusion sheet 15 is disposed between the lamp 11 and the liquid crystal display panel 1333. As an arrangement state, as shown in FIG. 32A, a configuration in which the lamp 11 is arranged at a part on the front surface of the lamp 11 may be employed. Alternatively, the lamp 11 may be formed in a character shape of ohm (Ω) as shown in FIG. The diffusion sheet 15b may be small (it is not necessary to cover the entire light exit surface of the parabolic mirror 12) because the cross section between the light emitting portion of the lamp 11 and the light emitting portion is difficult to see. Further, the diffusion sheet 15c may have an arc shape as shown in (c), or may have a planar shape as shown in (d). FIG. 33B shows the ratio of straight traveling light, and indicates that the smaller the ratio, the higher the degree of diffusion. This is the same in other drawings.
[0169]
The diffusion sheet 15 does not need to have uniform diffusion performance over the entire sheet. For example, as shown in FIG. 33, a part may be the diffusion unit 331. As shown in FIG. 33, the central part of the lamp 11 has a high degree of diffusion and the peripheral part has a low degree of diffusion. The diffusion sheet 15 makes it difficult for the observer to see the light emission shape of the lamp 11 when viewing the display panel 1333. When the observer changes the direction in which he looks into the magnifying lens 1336, the emission image of the lamp 11 moves depending on the viewing direction. Therefore, the diffusion portion 331 of the diffusion sheet 15 only needs to be large enough to cover the moving area of the emission image of the lamp 11.
[0170]
FIG. 33 shows the case where the lamps are arranged vertically, but it goes without saying that the structure shown in FIG. Further, the diffusion section 331 does not need to cover the entire lamp 11. For example, as shown in FIG. 35, a left diffusion unit 331a and a right diffusion unit 331b may be used. This is because the movement of the light emission image of the lamp 11 may be made difficult to see. Further, it is not necessary to be one diffusion part, and a dot-shaped diffusion point 332 may be formed as shown in FIG.
[0171]
The above is the case where the diffusion portion 331 or the diffusion point 332 is formed on the diffusion sheet 15. Alternatively, a diffusion point 332 may be formed on the surface of the lamp 11 as shown in FIG. As shown in FIG. 37B, the lamp 11 may be covered with a cap 72 to which a diffusing agent has been added. Further, by forming the reflection film 91 on the surface of the cap 72, high luminance can be realized. As the reflection film 91, a configuration in which a metal reflection film of Al or the like is directly formed on the inner surface or the outer surface of the cap 72, a configuration in which a metal reflection tube is covered, or the like is exemplified. FIG. 25 shows a system in which the illumination optical system is configured in a state where the reflection plate 22 and the lamp 11 are separated.
[0172]
In addition, there is a configuration in which the lamp 11 is inserted into the transparent holder 381 as shown in FIG. Examples of a material for forming the transparent holder 381 include glass, in addition to acrylic, polycarbonate, and epoxy resin. The reflection surface 22 is formed on the back surface of the transparent holder 381 by vapor deposition or the like.
[0173]
A configuration in which the exit surface on the diffusion sheet 15 side in FIG. 26 is a convex lens is also effective. This is because the light collection efficiency is improved. In addition, since the light emitted from the lamp 11 may be converted into parallel light by combining the convex lens and the reflecting surface 22 on the back surface, the positive power of the reflecting surface 22 and the convex lens surface is dispersed and small (the curvature is small). Help me).
[0174]
However, when the periphery of the lamp 11 is completely in contact with the transparent holder 381 (see FIG. 38), the heat of the lamp is easily conducted, the lamp 11 does not reach an appropriate temperature, and the emission luminance may decrease. . Further, after lighting, it takes a long time until the brightness reaches a predetermined value. The countermeasure is shown in FIG. A hole larger than the diameter of the lamp 11 of the transparent holder 381b is formed. A projection (convex portion) 401 is formed in the hole. The lamp 11 is held by the projection 401 and fixed at the center position. Also, a small space is created between the lamp 11 and the transparent holder 381b. Since air has poor thermal conductivity, the air in this space has a heat retaining effect.
[0175]
Further, as shown in FIG. 41B, by forming or disposing the prism 411 on the light emitting surface located on the right side of the configuration of FIG. 41A, the light condensing efficiency is increased, and high luminance can be realized. . As shown in FIG. 41 (c), by forming or disposing the diffusion sheet 15 (or diffusion plate) on the light emitting surface located at the right end, or by embossing, the image of the lamp 11 becomes invisible. Good image display can be realized.
[0176]
The lamp 11 is a hot-cathode type lamp, and has a large dependence on light emission luminance and temperature. In particular, when the temperature is 0 degrees Celsius or less, the light emission luminance may be significantly reduced. In the reference example related to the present invention, temperature compensation is performed by using a circuit configuration and a driving method as shown in FIG.
[0177]
The temperature detection circuit in FIG. 42A includes a thermistor or a posistor whose resistance value changes with temperature and a comparator circuit that detects that a predetermined temperature has been reached. The resistance value of the thermistor 421 decreases as the temperature decreases. Therefore R_sAnd S₁Voltage V_kChanges. Specifically, the voltage V_kIncreases with decreasing ambient temperature. E₁And E₂Is V_kThis is a reference voltage for comparison with. Voltage V_kIs E₁If it becomes higher, the output of the comparator 422a becomes a positive output. It is assumed that the ambient temperature at which this output becomes positive is set to 10 ° C. When the temperature drops further, the voltage V_kIs the reference voltage E₂When it becomes higher, the output of the comparator 422b also becomes a positive output. It is assumed that the ambient temperature at this time is set to −10 ° C. As described above, the logical output of the comparator 422 changes according to the ambient temperature, and the CPU 423 monitors the change in the logical output.
[0178]
When the output of the comparator 422a becomes a positive output, the CPU 423 switches SW of the analog switch 424b.₂Close. Then the resistance R₂And R_aBecome parallel and the voltage V_cBecomes larger. The current flowing through the FET 426 is I_a= R_ref/ V_cTherefore, the current flowing through the anode electrode 25 increases. When the ambient temperature further decreases and the output of the comparator 422b becomes a positive output, the CPU 423 sets the SW of the analog switch 424b.₃Close. Then the resistance R₂And R_aAnd R_bBecome parallel and the voltage V_cThe voltage becomes higher than before. Therefore R_refCurrent I_aBecomes larger, the current flowing to the anode 25 also increases, and high-luminance light emission can be performed.
[0179]
As the number of the comparators 422 increases, the current flowing through the anode electrode 25 depending on the ambient temperature can be more finely controlled. Therefore, temperature characteristic compensation of the lamp 11 can be performed with high accuracy. It goes without saying that, instead of the comparator 422, an IC for detecting temperature (an IC for measuring temperature and outputting digitally from a plurality of manufacturers) may be used.
[0180]
The thermistor 421 is preferably arranged close to the case of the lamp 11 as shown in FIG. In particular, it is preferable that the thermistor 421 is attached to a place where the emission of light from the light emitting unit is not blocked as shown in FIG. By adopting such a configuration, accuracy of temperature detection (particularly, lamp temperature) is improved.
[0181]
The lighting order of the lamps 11 should also be considered. Hereinafter, a method of lighting the lamp will be described. First, an external view of a video camera is shown in FIG. The description will be made mainly with respect to a video camera, but the present invention is not limited to this, and can be applied to a still camera, a head-mounted display, and the like.
[0182]
The video camera includes a photographing (imaging) lens unit 432, and the photographing lens unit 432 and the viewfinder unit 1321 are back-to-back. FIG. 43A is a perspective view in a state where no image is captured. When shooting (recording), the viewfinder 1321 is pushed down as shown in FIG. The viewfinder 1321 and the video camera main body 432 are connected by a connecting portion 434, and the connecting portion 434 can change the angle of 90 degrees. 43 (b) is to make it easier for the observer of the viewfinder to see the image displayed on the liquid crystal display panel 1333 and to take a picture easily.
[0183]
When the viewfinder 1321 is moved to the side as shown in FIG. 43B, the pressing of the switch (SW) 433 is removed, and the switch (SW) 433 is turned ON or OFF. Specifically, the switch (SW) 433 corresponds to a push switch. The switch (SW) 433 is connected to the voltage V₁Are connected in series with the resistor R to which is applied, and the other side is a grounded SW.
[0184]
When the SW (switch) is turned ON (or OFF), the CPU 423 detects that the SW (switch) is turned ON, and the CPU 423 detects the SW of the analog switch 424c.₄Close. Then, the filament voltage V₃Is applied to the filament 24, and the filament 24 of the lamp 11 is heated. When a current flows through the filament 24, the lamp 11 enters a pre-heating state. Therefore, the lamp 11 can emit light rapidly even at a low temperature by this preheating, so that the low-temperature characteristics of the lamp 11 can be improved.
[0185]
Next, the recording switch 435 in FIG. 43 is turned on. The information that the switch has been turned on is transmitted to the CPU 423, and the CPU 423 operates the SW of the analog switch 424a.₁By closing the voltage V₂Is applied to the anode electrode 25. Voltage V₂Is a voltage equal to or higher than the sustaining voltage. At this time, the output of the inverter 171 is at the L level. V₂Is lower than the discharge starting voltage, the lamp 11 does not discharge. Thereafter, the CPU 423 sets the output of the inverter 171 to the H level. Then, the capacitor C is connected to the anode electrode 25.₁Are superimposed on each other, the voltage of the anode electrode 25 becomes higher than the discharge starting voltage, and the lamp 11 emits light. When the lamp 11 emits light, the capacitor C₁Charge is discharged. When the above operation is performed, the reference voltage V_cIs set to a predetermined value.
[0186]
Capacitor C₁The larger the amount of charge to charge₁, The lower the temperature of the lamp 11 becomes, the easier the temperature of the lamp 11 becomes. FIG. 44A shows a change in the voltage applied to the anode electrode 25. The dotted line in FIG.₁And the discharge start voltage V is relatively small._a1Shows a change in the applied voltage when C is low (C₁The boost voltage is low). When the output of the inverter 171 becomes H level, the voltage of the anode electrode 25 becomes V_a1And immediately the capacitor C₁Voltage is discharged. FIG. 44B shows the change in the light emission luminance of the lamp at that time. Since the current flowing through the anode electrode 25 of the lamp 11 is a steady-state current, it takes a long time at low temperatures because the brightness becomes steady as indicated by the dotted line.
[0187]
On the other hand, capacitor C₁Has a large capacity and is relatively C₁The change in the applied voltage when the boosted voltage is high due to is shown by the solid line in FIG. When the output of the inverter 171 becomes H level, the voltage applied to the anode electrode 25 becomes V_a2And the lamp 11 normally starts discharging within 10 μsec. But C₁Since the charge amount is large, a current equal to or higher than the steady value is applied to the anode electrode 25 for a long time as shown by the solid line in FIG. Therefore, as shown by the solid line in FIG. 44B, the light emission luminance of the lamp 11 rapidly increases even at a low temperature. By doing so, the low-temperature characteristics of the lamp 11 can be compensated.
[0188]
Needless to say, as shown in FIG. 42B, low temperature compensation can be performed by supplying a current larger than a steady value to the filament 24 at the start of lighting. First, SW₅Is closed, the normal filament voltage V₃Higher voltage V₄Is applied to the filament 24. After a lapse of a predetermined period thereafter, SW₄To close the filament voltage V₃Is applied to the filament 24 and SW₅open. As described above, at the start of lighting of the lamp 11, by preheating the lamp 11 by applying an overcurrent to the filament 24, low temperature compensation of the lamp 11 can be easily performed.
[0189]
According to experiments, when the ambient temperature is -10 degrees, in order to perform practically sufficient low temperature compensation, a current of about 1.5 to 3.0 times the steady state anode current may be applied (reference is made to 25 degrees). ).
[0190]
FIG. 42 shows that the CPU 423 compensates for the current flowing to the anode electrode 25 of the lamp 11 based on the data of the temperature detection circuit. As shown in FIG. 45, the voltage V of the + terminal of the operational amplifier 425_cCan be directly changed by the thermistor 421 and controlled. The thermistor 421 becomes higher as the ambient temperature becomes lower, and the current I flowing through the anode 25 becomes higher._aBecomes larger. As an example, the anode current I in the case of the circuit constant of FIG._aAre shown in FIG. However, B of the thermistor is 4000.
[0191]
The lamp 11 emits light at a predetermined luminance by maintaining itself at a constant temperature. Therefore, if another object touches the lamp 11, the other object (such as the parabolic mirror 12) deprives the heat and makes it difficult to emit light (especially when the ambient temperature is low, the emission luminance decreases). As a configuration for improving this, there is a configuration for preventing the parabolic mirror 12 from touching the lamp 11 as much as possible, as shown in FIG. The lamp 11 is slightly in contact with or close to the parabolic mirror 12 at the point A. Further, the base substrate 14 is also brought into point contact with the three portions of the solder 29. With the above configuration, heat is hardly released from the lamp 11 and the temperature characteristics can be made very good.
[0192]
As a method for compensating for the temperature of the lamp 11, there is a method in which the light emission luminance of the lamp 11 is detected and feedback is performed to obtain a predetermined light emission luminance. The circuit diagram is shown in FIG. The photodiode temperature compensation circuit in FIG. 49 includes a photodiode 491, a resistor, and an operational amplifier 425. The light from the lamp 11 is a photodiode PD₁The current is excited in proportion to the amount of light emitted, and is converted into a voltage by a current-voltage conversion circuit using an operational amplifier 425a. The other photodiode PD₂491b is shielded from light. Therefore, the current-voltage conversion circuit converts the dark current of the photodiode 491b into a voltage by the operational amplifier 425b. The photodiode 491 described above is arranged near the lamp 11.
[0193]
The use of two photodiodes in this way is because the photodiode 491 has a large temperature dependency, so that the output of the two operational amplifiers 425a and 425b is canceled by the subtraction circuit of the subtraction circuit 425c (the influence of the photodiode 491b is reduced). It is. If the voltage applied to the + terminal of the operational amplifier 425d is changed in accordance with the light amount of the lamp 11, when the light amount of the lamp 11 is small (light emission luminance is low), the anode current I_aCan be increased, and the brightness of the lamp 11 can be increased to a predetermined value (desired value). Conversely, if the emission luminance of the lamp 11 is high, the anode current I_aCan be reduced, and the brightness of the lamp 11 can be reduced to a predetermined value (desired value).
[0194]
In the viewfinder according to the reference example related to the present invention, the observer brings the eye close to the eyepiece cover 1332 (see FIG. 1) (or the eye closely to the eyepiece ring 1335) to display the image displayed on the liquid crystal display panel 1333. You will see. That is, the position of the observer's pupil is substantially fixed. Assuming that all pixels of the liquid crystal display panel 1333 make light go straight, the magnifying lens 1336 emits light from the lamp 11 and enters the effective area of the parabolic mirror 12 after passing through the magnifying lens 1336. , Almost all enter the pupil of the observer. With the magnifying lens 1336, the observer can enlarge and view a small display image on the liquid crystal display panel 1333. That is, an enlarged virtual image can be seen.
[0195]
In the viewfinder, since the position of the pupil of the observer is almost fixed by the eyepiece cover 1332, the light source disposed behind the viewfinder may have narrow directivity. In a conventional viewfinder that uses a light box using a fluorescent tube as a light source, only light that travels within a small solid angle in one direction from an area approximately the same size as the display area of the liquid crystal display panel is used, and it is used in other directions. The traveling light is not used. That is, the light use efficiency is very poor.
[0196]
In the reference example relating to the present invention, a light source 11 having a small luminous body (or a luminous area is used with a limited area) is used, and light radiated from the luminous body at a wide solid angle is made parallel by a parabolic mirror 12 or the like. Convert to near light. In this case, the directivity of the light emitted from the parabolic mirror 12 or the like becomes narrow. If the observer's viewpoint is fixed, the light having the narrow directivity described above is sufficient for use in a viewfinder. If the size of the light emitting body is small, the power consumption is naturally small.
[0197]
As described above, the viewfinder of the reference example related to the present invention utilizes the fact that the observer views the display image while fixing the viewpoint. A normal direct-view liquid crystal display device requires a certain viewing angle, but a viewfinder is sufficient for use if a display image can be observed well from a predetermined direction. Therefore, the light emission area of the lamp 11 can be small, and low power consumption can be realized.
[0198]
In addition, although the small fluorescent discharge tube was illustrated as the lamp 11, it is not limited to this. For example, a flat fluorescent lamp 521 shown in FIG. 52 can be used. In a normal flat fluorescent lamp, a region 311a surrounded by a dotted line in FIG. 52 emits light. The area indicated by the dotted line 311a is larger than the effective display area of the liquid crystal display panel 1333. In the flat fluorescent lamp 521 shown in FIG. 52, only the shaded portion 311 emits light. In other words, the light emitting area is different from the flat fluorescent lamp manufactured by Ushio Inc. It can be easily understood that the power consumption is reduced when the light emitting area is small. In addition, if light emission only from the shaded portion 311 is sufficient, the outer dimensions of the flat fluorescent lamp 521 can be reduced.
[0199]
It is important that the light emitting area of the flat fluorescent lamp 521 is smaller than the area of the effective display area of the liquid crystal display panel 1333. This is a matter common to the lamp 11 of the reference example related to the present invention. That is, when the light emitting element 11 is viewed from the liquid crystal display panel 1333, the visible light emitting area is smaller than the effective display area of the liquid crystal display panel 1333. For example, in the discharge tube in FIG. 2A, the application area of the phosphor 23 is a considerably large area, but the entire area of the area is not compared with the area of the effective display area of the liquid crystal display panel 1333. The area of the light emitting region that can be used effectively is regarded as the light emitting area.
[0200]
Therefore, even if the light emitting area is large, if the light emitted from the lamp 11 is condensed by the condensing means such as the parabolic mirror 12 and the liquid crystal display panel 1333 cannot be illuminated, the light emitting area is actually regarded as small. When the liquid crystal display panel 1333 is in the transmissive state, the area that emits light reaching the observer is recognized as a light emitting area during light emission.
[0201]
Other LEDs can also be used as the lamp 11. FIG. 50 shows an LED and an explanatory diagram thereof. In FIG. 50, 503 is a resin lens, 502 is a light emitter, and 501 is a terminal. The luminous body 502 is constituted by a luminous chip. The light emitting chip is molded with a transparent resin (resin lens 503). The light emission luminance of the LED can be adjusted by controlling a voltage or a current applied to the light emitting chip.
[0202]
The surface of the LED mold resin (resin lens 503) can be used as a lens. In particular, as shown in FIG. 50B, it is preferable that the surface of the mold resin is spherical, and the light emitted from the light emitting body 502 satisfies the aplanatic condition. Assuming that the radius of curvature of the lens surface of the mold resin is r and the refractive index is n, the luminous body 502 is preferably disposed at a position S = (1 + 1 / n) · r away from the vertex 505 of the lens surface.
[0203]
At this time, the image of the light emitting body 502 by the lens surface 504 can be located at a position 508 that is separated from the vertex 505 of the lens surface by S ′ = (1 + n) · r. Since the size of the light emitting body 502 is sufficiently smaller than the diameter of the condensing means such as the parabolic mirror 12, it can be regarded as a point.
[0204]
In FIG. 50B, reference numeral 507 denotes a center of curvature of the lens surface 504, and reference numeral 506 denotes a normal line of the lens surface. When the light emitting body 502 of the LED is resin-molded and the emission surface is a spherical lens, and the light emitted from the light emitting body 502 satisfies the aplanatic condition with respect to the spherical lens, the light incident on the spherical lens from the LED Satisfies the sine condition, so that the luminance uniformity of the liquid crystal display device as viewed from the observer is improved.
[0205]
When the LED emits monochromatic light, one light-emitting chip (light-emitting body 502) may be used, but when white light is emitted, three chips 502a, 502b, and 502c of red, blue, and green are molded into one resin. In this case, particularly, the vicinity of the chip is molded with a resin 503b having a high light scattering property, and the outside thereof is molded with a resin 503a having a slightly high light scattering property. This is because, with such a configuration, three colors of red, blue, and green are mixed, and a good white color is obtained. The chromaticity can be easily changed by changing the current flowing through the three chips.
[0206]
FIG. 53 is an explanatory diagram of a state in which a viewfinder of a reference example related to the present invention is attached to a video camera. The body 1321 of the viewfinder is attached to the video main body 431 by a mounting bracket 1323. Reference numeral 1333 denotes a PD or TN liquid crystal display panel, and the diagonal length of the display screen is 0.5 inch. 533 is a drive circuit for the liquid crystal display panel 1333 mainly shown in FIG. Reference numeral 11 denotes a lamp having a diameter of 2.4 mm and emitting white light. A voltage is supplied to the lamp 11 from the light emitting element power supply circuit 532.
[0207]
The light emitting element power supply circuit 532 supplies the lamp 11 with a filament voltage of 2.1 V and an anode voltage (discharge sustaining) of 12 V. Both voltages are DC voltages. A pulse voltage of 18 (V) of 10 μsec is applied to the anode electrode 25 at the time of starting the lighting.
[0208]
On the other hand, a video signal is output from the CCD sensor 531 in the imaging means 432, applied to the video amplifier 191 of the liquid crystal display panel drive circuit 533, and an image is displayed on the liquid crystal display panel 1333. The video signal recorded on the video tape is reproduced by the reproduction circuit 534 and applied to the video amplifier 191. Reference numeral 202 denotes a battery attached to the video camera body 431, which supplies power to the light emitting element power supply circuit 532, the liquid crystal display panel drive circuit 533, and the reproduction circuit 534.
The viewfinder of the reference example related to the present invention can be applied not only to a video camera but also to an electronic still camera as shown in FIG. Used as a monitor attached to the still camera body 541. The configuration of the viewfinder of the reference example related to the present invention is applied to the viewfinder 1333. Since the capacity of the battery of an electronic still camera is also limited, low power consumption can be achieved by applying the viewfinder of the reference example related to the present invention.
[0209]
The items described above are also applicable to other viewfinders, video cameras, pocket televisions, head mounted displays, and the like, which are related to the present invention.
[0210]
The above configuration illuminates the liquid crystal display panel 1333 by converting the light from the lamp 11 into parallel light using the parabolic mirror 12 or the like. However, even if it is not a parabolic mirror as shown in FIG. 55, the liquid crystal display panel 1333 can be illuminated by using the convex lens 552 to convert the light emitted from the lamp 11 into parallel light.
[0211]
The light emitting area of the lamp 11 may be arranged at the focal point of the convex lens 552 as shown in FIGS. 58 (a) and 58 (b), or at a position farther than the focal length f as shown in FIG. 58 (c). The lamp 11 may be arranged at the bottom.
[0212]
Further, as shown in FIG. 58 (d), the lamp 11 may be arranged within a distance shorter than the focal length f. However, in the case of the configuration as shown in FIG. 58D, the reflection plate 551 is arranged on the rear surface of the lamp 11. This is to increase the apparent light emitting area. The total length of the viewfinder can be reduced. The viewfinder of FIG. 55 has a configuration employing the configuration of FIG. 58D.
[0213]
In addition, the illumination lens (convex lens 552) may be composed of a Fresnel lens 552a as shown in FIG. At that time, the incident surface of the Fresnel lens 552a is made concave. This is to prevent light emitted from the lamp 11 from being reflected when entering the lens. This is the same for the lens 552b in FIG. 59B and the lens 552d in FIG. 59C. The number of convex lenses is not limited to one, but may be two or more as shown in FIG. 59 (b), or may be one as shown in FIG. 5 (c). As a matter of course, a biconvex lens may be used. As shown in FIG. 60, one of the lenses 603 may have a convex surface 601 and the other surface may have a Fresnel surface 602. Of course, it may be manufactured by bonding a plano-convex lens and a Fresnel lens.
[0214]
Note that a lens used for illumination of the liquid crystal display panel 1333 such as the convex lenses 552 and 603 is preferably made of polycarbonate. Since the refractive index is higher than acrylic, the lens thickness can be reduced. Polycarbonate has a large dispersion coefficient. However, since it is used for an illumination system, color shift does not occur due to a wavelength fraction, which is practically sufficient.
[0215]
FIG. 1 shows an illumination optical system composed of a reflector such as a parabolic mirror 12 and a lamp 11. FIG. 55 shows an illumination optical system including an illumination lens 552, a lamp 11, and a reflection plate 551. An auxiliary lens 553 is arranged on the light emission side of the liquid crystal display panel 1333. The reflection plate 551 is arranged on the rear surface of the lamp 11. The lamp 11 is arranged so that the focal point f of the illumination lens 552 is located in front of the light emitting surface of the lamp 11 (see FIG. 58A), the lamp 11 is arranged behind the lamp (see FIG. 58B), and the lamp 11 Is arranged at a distance position longer than the focal length f (see FIG. 58 (c)), and a configuration where the lamp 11 is arranged within the focal length (see FIG. 58 (d)). 58 (d) is the most preferable because the total length of the viewfinder becomes short.
[0216]
Light reflected from the lamp 11 to the rear surface is reflected by the reflector 551 and enters the illumination lens 552. That is, the reflection plate 551 can be regarded as apparently having a large luminous body image of the lamp 11. In the case of FIG. 58 (a) or FIG. 58 (b), the light in a part of the light emitting region of the lamp 11 is collected. Therefore, high brightness display can be realized by setting the light collecting area to the area where the lamp generates the highest brightness.
[0217]
As shown in FIG. 57, a major feature is that the principal ray incident on the liquid crystal display panel 1333 is made substantially perpendicular to the surface of the liquid crystal display panel 1333 by the illumination lens 552 and the auxiliary lens 553. This is because the TN liquid crystal display panel can satisfactorily modulate light that is substantially perpendicular to the panel surface, and can realize good black display (in the NW mode). When light is obliquely incident on the panel surface of the liquid crystal display panel 1333, the arrangement direction of the liquid crystal molecules arranged by applying a voltage does not coincide with the traveling direction of the incident light, and light leaks from the analyzer. It becomes impossible to display black.
[0218]
If there is no auxiliary lens 553, the light radiated from the lamp 11 needs to squeeze toward the magnifying lens 1336 as shown by 51b. The effective diameter of the magnifying lens 1336 is usually small (to limit the direction in which the observer views the display image on the panel 1333, and to reduce the diameter of the magnifying lens 1336 to make it compact or the like). Therefore, it is necessary to increase the positive power of the illumination lens 552 and make the diameter of the illumination lens 552 larger than the effective diagonal length of the liquid crystal display panel 1333 (the diagonal length of the screen display area). Therefore, the lens center thickness of the illumination lens 552 is inevitably increased, and the viewfinder becomes large. Naturally, the light incident on the liquid crystal display panel 1333 also becomes oblique, so that the display contrast decreases. The auxiliary lens 553 has the effect of reducing the thickness of the illumination lens 552 and the effect of improving the display contrast by making the light incident on the liquid crystal display panel 1333 almost vertical. FIGS. 140 and 141 are examples of optical design.
[0219]
The illumination lens 552, the liquid crystal display panel 1333, and the auxiliary lens 553 are attached to a cylindrical body 1321b (see FIG. 55), and the body 1321a to which the cylindrical body 1321b and the lamp 11 are attached and an eye cap (eyepiece cover 1332). Is configured to be able to freely operate (movable) with the body 1321c to which is attached.
[0220]
FIG. 56 is a configuration diagram in which the entire length of the viewfinder is shortened by being movable. The distance between the lamp 11 and the illumination lens 552 is reduced, and the distance between the auxiliary lens 553 and the magnifying lens 1336 is also reduced. FIG. 56 is a cross-sectional view when the viewfinder is not used. The overall length is shortened and portability is improved. When the viewfinder is used, it is stretched as shown in FIG. 55 so that the illumination lens 552 is located at a position where the light emitted from the lamp 11 can be favorably collected.
[0221]
It should be noted that the inner surface of the body 1321 of the viewfinder is made black or dark to absorb light. This is to prevent the display contrast of the display panel 1333 from being lowered by light irregularly reflected by the convex lenses 552, 553 and the like.
[0222]
Note that a polycarbonate resin can be used for the auxiliary lens 553 similarly to the illumination lens 552. Polycarbonate has a higher refractive index than acrylic or the like and can reduce the thickness of the lens, so that the weight of the viewfinder can be reduced.
[0223]
As shown in FIG. 56, the filament 24 of the lamp 11 is arranged at an angle of θ from the front position of the lamp. As will be described later, θ is set to 30 degrees or more and 60 degrees or less. The reason will be described below with reference to FIG. The terminal 16a (see FIG. 2) is connected to the point A of the filament 24, and is set to the ground potential (GND). A terminal 16b is connected to the point B of the filament 24, and a filament voltage is applied. In FIG. 9, the reflection film 91 is formed on the inner surface or the outer surface of the lamp case 21. However, the case where the reflection film 91 is used as the light emitting element 11 of the viewfinder of the reference example related to the present invention is not limited thereto. A material that is not formed, such as 8, may be used.
[0224]
FIG. 61B shows an arrangement of the filament 24 and the anode electrode 25. The anode electrode 25 is formed in a planar shape, and is attached to the tip of the terminal 16c. The longitudinal direction of the filament 24 and the longitudinal direction of the anode electrode 25 are arranged so as to be orthogonal to each other.
[0225]
FIG. 61 (a) shows a measurement of the luminance distribution in the circumferential direction based on the midpoint of the diameter of the lamp case 21 in the arrangement state of the filament 24 and the anode electrode 25 as shown in FIG. 61 (b). Shown in It is assumed that the reflection film 91 is not formed on the lamp case 21. As is clear from FIG. 61A, the luminance becomes highest at 45 degrees (DEG.) And 315 degrees. Further, the luminance becomes lowest at 0 degrees and 180 degrees.
[0226]
The thermoelectrons emitted from the filament 24 are accelerated by the anode voltage of the anode electrode 25. Therefore, the greater the potential difference between the filament 24 and the anode electrode 25, the greater the acceleration and the greater the amount of generated ultraviolet light. Since the point A of the filament 24 is GND, the potential difference between the anode electrodes 25 is large. Therefore, as shown in FIG. 61 (a), the emission luminance becomes highest at the angle between the longitudinal direction (0-180 degrees) of the filament 24 and the central portion in the longitudinal direction (90-270 degrees) of the anode electrode 25. is there. In the viewfinder of FIG. 55, in the case of FIGS. 58 (a) and (b), it is more advantageous to direct the highest luminance area to the liquid crystal display panel 1333 side. In the case of FIG. 58B, it may be more advantageous to arrange as shown in FIG. In any case, when the liquid crystal display panel 1333 is illuminated by regarding the lamp 11 as a point light source, it is advantageous to arrange it as shown in FIG. Therefore, in the case of FIG. 55, the angle range of 30 degrees or more and 60 degrees or less with respect to the longitudinal direction of the filament 24 may be directed toward the liquid crystal display panel.
[0227]
It should be noted that the clockwise direction is 30 degrees or more and 60 degrees or less, but it is needless to say that the range of 300 degrees or more and 330 degrees is 30 degrees or more and 60 degrees in the counterclockwise direction.
[0228]
The lowest brightness at 0 degrees and 180 degrees is due to the shadow of the filament 24. Therefore, it is not preferable to use this surface facing the surface A (the front of the lamp 11).
[0229]
In order to further improve the light emission luminance of the surface A, it is preferable to form a depression in the lamp case 21 as shown in FIG. This is because the emission luminance is determined depending on whether or not a fluorescent substance is present in the vicinity of the generated ultraviolet light. The higher the ultraviolet density, the higher the emission luminance. However, if it is too close to the filament 24, the oxide of the filament 24 may be scattered to the phosphor and blackened to lower the luminance. In any case, as shown in FIG. 61 (c), if a depression, a concave portion, or a flat portion is formed, the generated ultraviolet rays are effectively irradiated to the phosphor, and the emission luminance of the A surface (light emission surface) is increased.
[0230]
The method of configuring the viewfinder with the highest light emission luminance portion as the target in consideration of the arrangement direction of the filament 24 of the lamp 11 described in FIG. 61 can be applied to other display devices. A display device having a light emitting unit and a display panel according to a reference example relating to the present invention corresponds to the viewfinder of the present invention. Therefore, the viewfinder of the present invention includes a monitor section used for a video camera, a display section of a pocket television, a display section of a mobile phone, a display section of an electronic still camera, a direct-view liquid crystal television, a head mounted display, and the like in the concept of the viewfinder. Therefore, the configuration method of the reference example related to the present invention described in this specification can be applied not only to other video cameras but also to the following display devices.
[0231]
FIG. 62 is an explanatory diagram when the method of FIG. 61 is applied to a direct-view display device. As shown in FIG. 62, the filament 24 in the lamp 11 is arranged to be inclined in a predetermined direction as shown in FIG. 61, and the A surface is arranged toward the edge of the light guide plate 621. The rear surface of the lamp 11 is covered with a reflection plate 551 or the like to increase the output light to the A surface. The reflection plate 551 (or the reflection film) is exemplified by Silverlux manufactured by Sumitomo 3M Limited. Many other sheets having a reflectance of 90% or more on which Al is deposited are commercially available. Of course, a reflection plate of Al or the like may be used.
[0232]
It is more preferable to make the surface A concave, because the light emission luminance increases. The light radiated from the lamp 11 is transmitted while being reflected in the light guide plate 621, and is scattered and radiated toward the display panel 1333 when entering the diffusion portion (622 f). The diffusion plate 15 is for preventing the pattern of the diffusion portion 621 from being seen. Further, as the distance from the lamp 11 increases, the formation area of the diffusion portion 622 increases. This is to make the luminance of the light guide plate 621 uniform.
[0233]
Since the lamp 11 is of a hot cathode type, the anode current I_aThe display brightness of the light guide plate 621 can be easily adjusted only by adjusting. In addition, since light is emitted at a low DC voltage of 20 (V) or less, a high voltage is not required unlike a cold cathode lamp, and radio wave radiation noise does not occur.
[0234]
Naturally, a reflecting plate 551 made of metal as shown in FIG. 63 may be used. The reflection plate 551 is larger than the width of the display area of the display panel 1333. What is necessary is just to comprise using the reflection sheet etc. which were illustrated previously. In addition, a prism plate 631 may be provided to increase light incident on the display panel 1333. Since the light emission pattern of the lamp 11 may be displayed as it is, the diffusion plate 15 is disposed between the lamp 11 and the display panel 1333.
[0235]
The viewfinder shown in FIG. 55 has a configuration in which the effective diameter of the illumination lens 552 is smaller than the opening of the reflector 551.
[0236]
It is effective to bring the reflector 551 closer to the lamp 11 and increase the area as shown in FIG. This is because the lamp 11 can be brought closer to the illumination lens 552, and the total length of the viewfinder can be shortened. By increasing the size of the reflector 551 as compared to FIG. 55, the apparent light emitting area of the lamp 11 increases.
[0237]
In FIG. 64, a light beam 51a emitted from the front surface (region a) of the lamp 11 is directly incident on the illumination lens 552, passes through the liquid crystal display panel 1333, the auxiliary lens 553, and the magnifying lens 1336, and the eye point 641 of the observer. (The pupil of the observer). On the other hand, light emitted from the side surface (region b) of the lamp 11 is reflected once by the reflector 551, enters the illumination lens 552, becomes a light beam 51b, and enters the eye point 641 of the observer. The light emitted from the rear surface (region c) of the lamp 11 is reflected by the reflector 551, returns to the lamp 11, and is scattered again by the phosphor 23, thereby contributing to the improvement of the brightness of the lamp 11. That is, in the configuration of FIG. 64, light emitted from the entire periphery of the lamp 11 can be effectively used, and the light use efficiency is high.
[0238]
The aperture diameter k of the reflection plate 551 is preferably d / 2 <k, where d is the width of the effective display area of the liquid crystal display panel 1333 (4 for a 4: 3 screen).
[0239]
In the configuration of FIG. 64, the lamp 11 and the reflection plate 551 (or reflection sheet) are separated from each other. A configuration in which a transparent resin 381 is filled between the reflector 551 and the lamp 11 as shown in FIG. 65 is also effective. This is because the transparent resin 381 has an effect of keeping the lamp 11 warm and an effect of preventing damage due to impact. Further, as shown in FIG. 66, it is effective to make the light exit surface of the transparent resin (transparent holder 381) into a convex lens shape (or a convex shape). This is because the light exit surface functions as a lens having positive power, and the thickness of the illumination lens 552 can be reduced.
[0240]
Note that the transparent resin may be made of a transparent inorganic material such as glass. Also, as shown in FIG. 40, a configuration in which a slight space is provided between the lamp 11 and the transparent resin (transparent holder 381) to improve the heat retaining effect of the lamp 11 is also effective. Further, the illumination lens 552 and the reflection plate 551 may be integrated to be configured as shown in FIG.
[0241]
In the configuration of the viewfinder using the auxiliary lens 553 as shown in FIG. 55, it is a problem that dust adheres to the flat surface of the auxiliary lens 553. This is because dust may be seen by an observer near the display surface of the liquid crystal display panel 1333. Therefore, the plane portion of the auxiliary lens 553 needs to be 3 mm or more, preferably 5 mm or more, larger than the light emission surface of the display panel 1333. As another configuration, as shown in FIG. 68, a method is also effective in which the auxiliary lens 553 is fitted into the panel holder 681, and the space between the light emitting surface of the display panel 1333 and the auxiliary lens 553 is sealed to prevent dust from entering. According to this configuration, dust does not adhere to the flat portion of the auxiliary lens 553, and dust does not adhere to the surface of the display panel 1333. The auxiliary lens 553 may be resin-molded according to the size of the opening of the panel holder 553. In order to further improve the sealing property, a cushioning material such as rubber may be interposed between the panel holder 681 and the auxiliary lens 553.
[0242]
It is also effective to inject a transparent resin 381 between the auxiliary lens 553 and the display panel 1333 to integrate them. The transparent resin 381 is selected to have a refractive index substantially equal to that of the auxiliary lens 381. Acrylic adhesive, silicone gel, ethylene glycol, epoxy adhesive and the like are exemplified. According to this configuration, the interface reflection of the auxiliary lens 553 is eliminated and the light transmittance is improved. In addition, the liquid crystal display panel 1333 and the auxiliary lens 553 also eliminate interference and improve image display quality.
[0243]
In FIG. 56, it has been described that when the viewfinder is not used, the distance between the illumination lens 552 and the lamp 11 is shortened to improve portability. However, even if the distance is shortened, as shown in FIG.₁And the diameter d of the lamp 11₂It cannot be shorter than the sum of
[0244]
In order to solve this, there is a method of disposing the lamp 11 below the illumination lens 552 at the time of storage as shown by a dotted line in FIG. The lamp 11 can be rotated by 90 degrees around the point A. FIG. 70 shows a view from the lateral direction. The liquid crystal display panel 1333 needs to be mounted on the panel holder 681 to hold it. The vertical length of the illumination lens 552 may be the vertical length of the liquid crystal display panel 1333 (for example, 9 when the panel is 16: 9) + α. Therefore, a space is formed in the upper and lower portions of the illumination lens 552. This is particularly remarkable when the size of the liquid crystal display panel 1333 is horizontally long as in a wide-capacity panel. The lamp 11 is housed in this space by rotating the lamp 90 degrees.
[0245]
As the storage mechanism, first, the lamp 11 is rotated about the point A and is pushed down. Next, the illumination lens 552 and the liquid crystal display panel 1333 are shifted rearward as shown in FIG. Those skilled in the art will easily consider the lamp rotation mechanism and the like. The key point is that there are spaces above and below the illumination lens 552.
A configuration in which the lamp 11 is pulled out from the optical axis is also conceivable. This method is shown in FIGS. 71 to 73. The lamp 11 is attached to a socket 711, and a knob 712 is attached to the socket 711. The observer grasps the knob 712 and retracts the lamp 11 from the optical axis 715 as shown in FIG. 72 during storage (when the viewfinder is changed from the use state to the non-use state). Next, when the lamp 11 is pulled out, the illumination lens 552, the liquid crystal display panel 681 and the like are moved backward by a motor or the like, and the state shown in FIG. 73 is obtained.
[0246]
It is desirable that the magnifying lens 1336 be attached to the cylindrical body 714 so as to be separated from the body 713. Then, at the same time as the illumination lens 552 is lowered backward, it is accommodated in the body 713 as shown in FIG. Such a configuration is easy. For example, there is a configuration in which a shooting lens protrudes forward when a switch is turned on in a compact camera. This mechanism may be adopted. With the same configuration, it can be realized that the illumination lens 552 is mechanically lowered backward.
[0247]
73, the overall length of the viewfinder can be greatly reduced by a configuration in which the lamp 11 is pulled out from the optical axis 715 or a configuration in which the lamp 11 is stored below or above the illumination lens 552 as shown in FIG. Is good. Further, by storing the body 714 holding the magnifying lens 1336 in the body 713, the overall length can be significantly reduced.
[0248]
Although the auxiliary lens 553 is fitted in the panel holder 681 in FIG. 68, it is preferable that the illumination lens 552 be fitted in the panel holder 681 as shown in FIG. This is because dust does not adhere to the back surface of the liquid crystal display panel 1333, and good image display can be realized. Further, the space between the illumination lens 552a and the liquid crystal display panel 1333 is filled with a transparent resin 381b or the like, because the interface loss is eliminated and the light utilization efficiency is improved. It is needless to say that the magnifying lens 1336, the auxiliary lens 553, the illumination lens 552a and the like can be replaced by Fresnel lenses.
[0249]
As a method of shortening the entire length of the viewfinder, as shown in FIG. 75, there is a configuration in which the optical axis 715b of the lamp 11 and the optical axis 715a of the magnifying lens 1336 are substantially orthogonal to each other. A mirror 751 is arranged to bend the optical axis 715. Light from the lamp 11 is collected by the illumination lens 552 and bent by the mirror 751 to illuminate the liquid crystal display panel 1333. The depth d can be reduced as compared with FIG. FIG. 76 shows a perspective view at that time for easier understanding. The lamp 11 may be arranged in the direction shown in FIG. 76 or the direction shown in FIG. 77, or may be arranged vertically as shown in FIG. The illumination lens 552 may be replaced with a Fresnel lens 552b as shown in FIG.
[0250]
Further, there is also a configuration in which the liquid crystal display panel 1333 is arranged horizontally as shown in FIG. It is promising as a configuration to shorten the overall length. In particular, it is desirable to adopt this configuration when a space can be provided above the viewfinder.
[0251]
Next, a description will be given of a viewfinder according to a reference example relating to the present invention in which the illumination lens 552 is a planar condensing unit such as a Fresnel lens and a diffusion plate (sheet) 15a is disposed between the Fresnel lens 552 and the liquid crystal display panel 1333. I do.
[0252]
The reference example relating to the present invention uses a lamp 11 having a small light-emitting area, and converts light emitted from the light-emitting area at a wide solid angle into light that is nearly parallel by a Fresnel lens 552, as before. In this case, the directivity of the light emitted from the lens becomes narrow. If the observer's viewpoint is fixed, the light having the narrow directivity described above is sufficient for use in a viewfinder. As described above, when the size of the light emitting region is small, the power consumption is naturally small.
[0253]
As described above, the viewfinder of the reference example related to the present invention utilizes the fact that the observer views the display image while fixing the viewpoint. A normal direct-view liquid crystal display device requires a certain viewing angle, but a viewfinder is sufficient for use if a display image can be observed well from a predetermined direction.
[0254]
The viewfinder shown in FIG. 83 uses a Fresnel lens 552 to collect light emitted from the lamp 11. The Fresnel lens 552 is manufactured using acrylic plastic or glass such as BK7. The Fresnel lens 552 has a state in which when the light from the lamp 11 is incident on the display panel 1333, it becomes substantially parallel light. The plane of the Fresnel lens 552 is provided with a single-layer anti-reflection coating to prevent light reflection.
[0255]
Although one Fresnel lens 552 is used in FIG. 83, a plurality of lenses may be used as in FIG. 59B. The same applies to the illumination lens 552 in FIG. 55 and the like, but the lens is preferably an aspheric surface such as an elliptical surface. With an aspherical surface, it is possible to satisfactorily illuminate the periphery of the display panel 1333, and it is possible to increase the light amount ratio (peripheral light amount ratio) between the center and the periphery of the display panel 1333.
[0256]
The light on the rear surface of the lamp 11 is reflected as shown by the reflection plate 831. The F values of the magnifying lenses 1336a and 1336b are about 3.5 to 4.5, respectively. Therefore, it is preferable that the F value of the light incident on the display panel 1333 (the F value of the illumination system) be lower than that. Of course, the magnifying lens 1336a may be configured as a single piece as shown in FIG.
[0257]
The F value of the illumination light is specifically 4 or less. The F value is a design item determined by the distance between the display panel 1333 and the lamp 11, the effective diagonal length of the display panel 1333, and the power of the Fresnel lens 552. The area of the light-emitting region of the lamp 11 is set to be 1 mm or more and 10 mm or less in diameter.
[0258]
In particular, when a TN liquid crystal display panel is used as a light modulator (liquid crystal display panel 1333), the diameter is generally set to 1/10 or more and 1/2 or less of the effective diagonal length of the panel. Preferably, it is 1/8 or more and 1 / (2.5) or less. In particular, for example, the diameter is set to 2 mm or more and 5 mm or less for 0.5 inch, and 4 mm or more and 10 mm or less for an effective diagonal length of 0.7 inch.
[0259]
Note that the diameter refers to an area of a region that can be condensed by the Fresnel lens 552 and irradiated to the liquid crystal display panel 1333. Therefore, even if the diameter is large, if the Fresnel lens 552 cannot collect light, the diameter is effectively regarded as small.
[0260]
When a PD liquid crystal display panel is used for the view finder of the reference example related to the present invention, a pinhole plate should be arranged in front of the lamp 11. Of course, when the light emitting area of the lamp 11 is very small, it goes without saying that a pinhole plate is not required.
[0261]
The pinhole plate has a function of making a region where light is emitted from the lamp 11 a small region. When the area of the hole increases, the display image on the PD liquid crystal display panel becomes brighter, but the contrast decreases. This is because the amount of light incident on the Fresnel lens 552 increases, but the directivity of the incident light deteriorates. For example, when the diagonal length of the display area of the liquid crystal display panel 1333 is 28 mm (1.1 inches), the area that emits light is approximately 15 mm.²You should: This corresponds to the diameter of a pinhole with a diameter of approximately 4 mm. Preferably 10 mm²Should be:
[0262]
However, if the diameter of the hole is too small, the directivity of light becomes narrower than necessary, and when the viewfinder is viewed, the display screen becomes extremely dark even if the viewpoint is slightly shifted. Therefore, the area of the hole is at least 2 mm²The above area should be secured. As an example, when the hole has a straight line of 3 mm, the brightness of the display screen is equal to or higher than that of a viewfinder using a conventional surface light source, and the contrast at that time is 20 or more.
[0263]
The light emitting area, or hole, should be considered in the range of 1 mm to 5 mm or less in diameter. If the ratio is defined by the display area and the area ratio of the hole for emitting light, it must be 20: 1 or less. Preferably it is 40: 1 or less. However, from the viewpoint of the viewing angle, it is preferable to set the ratio to 200: 1 or more. The above applies to other viewfinders of the reference example related to the present invention.
[0264]
Items related to the filament 24 of the lamp 11 are arranged so that the side A faces the display panel 1333 side as shown in FIG.
[0265]
A reflector 831 is provided on the rear surface of the lamp 11. This is because light emitted backward in the viewfinder is wasteful. By arranging the reflecting means (reflecting plate 831) on the rear surface of the lamp 11, the amount of luminous flux radiated from the front surface increases, and the brightness of the lamp 11 can be increased.
[0266]
FIG. 41 shows an example of an optical design when the Fresnel lens 552 is an aspherical lens and the diffusion plate 15 is not provided.
[0267]
As the reflection plate 831, an aluminum plate or a stainless plate processed is exemplified. Alternatively, a thin film of aluminum or the like may be deposited on the back surface of glass or the like. Further, as shown in FIG. 90, the reflecting plate 831 may be disposed so as to be in close contact with the lamp 11, and the space between the lamp 11 and the reflecting plate 831 may be filled with a transparent adhesive 381 or the like. The transparent adhesive 381 fixes the reflector 831 and the lamp 11 integrally and facilitates mounting on the body 1321, reduces the loss due to interface reflection between the reflector 831 and the lamp 11, and emits the light to the front. It has the function of increasing the amount of light.
[0268]
Further, as shown in FIG. 83 (b) and FIG. 90, the vertex of the lamp 11 is a flat surface. This is because the reflector 831 can be easily attached to the lamp 11 (if the apex is spherical, it is difficult to attach), and the light flux at the apex is reflected to effectively guide the light to the front of the lamp. . Of course, the reflection plate 831 and the lamp 11 may be arranged as shown in FIG.
[0269]
By configuring the lamp portion as shown in FIG. 83 (b), the luminous flux at the rear and top portions of the lamp 11 can be effectively guided to the lamp side surface, and the light emission luminance to the front surface can be increased. According to the experiment, the luminance was improved by about 30% or more when the reflector 831 was provided, and the luminance unevenness on the front face was significantly reduced as compared with the case without the reflector 831.
[0270]
Note that the color temperature of the lamp 11 can be adjusted if one color of the reflecting plate 831 can be favorably reflected. For example, if the reflection plate 831 reflects red strongly, the color temperature of the lamp 11 decreases. Conversely, if blue is strongly reflected, the color temperature will increase. As a realizing means, a pigment or a pigment may be added to the adhesive 381. This also applies to the case where the reflection plate 831 itself is colored. For example, red aluminum foil.
[0271]
Light emitted from the lamp 11 uniformly illuminates the effective display area of the liquid crystal display panel 1333 by the Fresnel lens 552. However, it is better that the illuminated range is slightly wider than the effective display area diameter. This is because, when a display image on the display panel 1333 is viewed from the magnifying lens 1336, even if the viewing angle is slightly changed, the four corners of the panel are prevented from becoming dark.
[0272]
The light emitting area of the lamp 11 is set near the focal point of the condenser lens 522. 58A, when the focal point f of the lens is on the surface of the light emitting area of the lamp 11 as shown in FIG. 58A, the focal point of the lens is the rear end of the lamp 11 as shown in FIG. In this case, as shown in FIG. 58C, the case where the focal point of the lens is at the defocused position is also included. According to the experiment, the state shown in FIG. 58B shows that the distance d from the vertex of the condenser lens 552 to the rear end of the lamp 11 becomes shorter, and the light emitting area of the light emitting element (the lamp 11) as viewed from the condenser lens 552. Is large, so that the viewing angle of the viewfinder is widened, which is preferable. When the diameter of the lamp 11 was 5.1 mm and the liquid crystal display panel 1333 was 0.5 inch, d was about 12 mm, and when it was 0.7 inch, d was about 17 mm.
[0273]
When the liquid crystal display panel 1333 is a TN liquid crystal display panel, the display contrast is improved when the directivity of light incident on the liquid crystal display panel 1333 is narrow. This is because the analyzer 1334b (see FIG. 23) is most used when the orientation direction of the liquid crystal molecules in the liquid crystal layer of the liquid crystal display panel 1333 (when voltage is applied to the liquid crystal layer) and the direction of incident light match. This is because transmitted light is reduced.
[0274]
The conventional viewfinder includes a surface light source, and light from the surface light source enters the liquid crystal display panel 1333. The light from the surface light source is scattered light (light without directivity). Therefore, the orientation direction of the liquid crystal molecules of the liquid crystal display panel 1333 (when a voltage is applied to the liquid crystal layer) does not match the direction of the incident light. Therefore, the amount of light transmitted through the analyzer 1334b increases, and the display contrast deteriorates.
[0275]
On the other hand, in the viewfinder and the like of the reference example related to the present invention, the light emitted from the light emitting element (lamp 11) is converted into light with narrow directivity by using a condensing means (such as a Fresnel lens 522 or a reflector 831). Is done. Therefore, light with narrow directivity is incident on the liquid crystal display panel 1333. Therefore, the alignment direction of the liquid crystal molecules (when a voltage is applied to the liquid crystal layer) matches the direction of the incident light, and the display contrast is improved. This is the same even when a PD liquid crystal display panel is used as the light modulating means. That is, although the PD liquid crystal display panel does not use the analyzer 1334b, the liquid crystal molecules in the water-droplet liquid crystal 245 (see FIG. 24) are aligned in one direction, and the light transmittance is determined when the aligned direction matches the direction of the incident light. This is because the display contrast is improved as a result of the improvement. The same applies to the viewfinder of another reference example related to the present invention shown in FIG. 1 and the like.
[0276]
In FIG. 83 and the like, the pitch of the Fresnel lens 552 is very wide, but this is for ease of illustration, and in fact, it is usually formed at a very short pitch of at least 1 mm or less. is there.
[0277]
On the light exit surface of the Fresnel lens 552, a diffusion plate 15 is disposed as light scattering means. Examples of the diffusion plate 15 include those formed by combining a special glass fiber and a polycarbonate resin sold by Tsutsunaka Plastics Industry Co., Ltd. (for example, ECB1020 and ECB1010). However, this seems a bit too diffuse. The light-up series MX100, SX100, SH100, etc. of Kimoto Corporation are appropriate. The diffusion plate 15 having a total light transmittance (%) of 80% or more is used. If the total light transmittance is poor, the amount of light reaching the liquid crystal display panel 1333 is reduced, and the display screen is darkened. As a result, the power consumption of the light source is increased. However, if the total light transmittance (%) is high, the grooves of the Fresnel lens 552 are visible through the liquid crystal display panel 1333.
[0278]
It may be argued that the diffusion plate 15 used in the viewfinder or the like of the reference example related to the present invention is not the same as the diffusion plate of the conventional viewfinder. However, the configuration, purpose, and effect are completely different as described below.
[0279]
In the conventional view finder, as shown in FIG. 138, light from a fluorescent tube is scattered by a diffusion plate 15a to form a surface light source. The surface light source ideally emits a luminous flux in all directions, and is almost the same (perfectly diffused surface) regardless of the luminance measured from any direction. The reason why the light emission pattern of the fluorescent tube is visible as shown in FIG. 138 is that a large amount of light flux travels straight through the diffusion plate 15a. This is because the use of a surface light source is incomplete, and the diffusion plate 15a is ideally for obtaining a perfect diffusion surface. Therefore, scattered light enters the liquid crystal display panel 1333.
[0280]
On the other hand, the view finder and the like of the reference example related to the present invention described in the section of this embodiment collects the light from the lamp 11 by a condensing means (illumination lens, Fresnel lens 552) to form substantially parallel light. (Light with narrow directivity), and the converted light passes through the diffusion sheet (plate) 15 and enters the liquid crystal display panel 1333. The diffusion sheet (plate) 15 is not intended to form a surface light source. Since moire is generated due to interference between the pixels of the liquid crystal display panel 1333 and the grooves of the Fresnel lens 552 or the like, it is used to slightly widen the directivity of light. Also, it makes the groove of the Fresnel lens 552 that is faintly visible through the magnifying lens 1336 or the like difficult to see. Therefore, light with narrow directivity mainly enters the liquid crystal display panel 1333. That is, light having a narrow directivity is dominant. In the reference example related to the present invention, light slightly scattered by the diffusion plate 15 is incident on the liquid crystal display panel 1333 in an auxiliary manner.
[0281]
From the above, even if the diffusion plate 15 and the diffusion plate 15a have the same function of "scattering" light, they basically differ in "whether or not they form a surface light source". Further, while the conventional viewfinder makes light having no directivity incident on the liquid crystal display panel 1333, the viewfinder and the like of the reference example related to the present invention described in this section employ light collecting means (condensing lens, This is fundamentally different in that the light is converted into light with narrow directivity by the Fresnel lens 552) and the light with narrow directivity is incident on the liquid crystal display panel 1333.
[0282]
The light may interfere with the pixel pitch Pd of the liquid crystal display panel 1333 and the pixel pitch Pr of the Fresnel lens 552, and moire may occur.
By arranging the diffusion plate 15 between the Fresnel lens 552 and the liquid crystal display panel 1333, even if moire occurs, it is difficult to see. The pitch P of the generated moire is
[0283]
(Equation 1)

[0284]
Can be expressed as The maximum moiré pitch is the minimum
[0285]
(Equation 2)

[0286]
And the degree of modulation of moiré decreases as n increases. Therefore, Pr / Pd may be determined so as to satisfy (Equation 2). However, since the Fresnel lens 552 is formed with concentric grooves and the pixels of the liquid crystal display panel 1333 are arranged in a matrix, it is somewhat difficult to determine the pitches Pr and Pd in (Equation 2). However, a value that can further reduce the occurrence of moiré can be derived through experiments and the like in consideration of (Equation 2).
[0287]
Note that, in (Equation 2), n is an integer value. The pixel pitch Pd is a constant value because it is determined by the pixel size of the liquid crystal display panel 1333 and the like. Therefore, it is necessary to determine the pitch Pr of the Fresnel lens 552 at an optimum value in consideration of the production of the Fresnel lens 552. Since n is an integer value, Pr is a quantum value. At the time of manufacturing the Fresnel lens 552, it is difficult to determine the value of Pr by matching the above equation due to problems in accuracy and processing. Therefore, the value of Pr slightly deviates from the ideal value. In practice, there is no problem even if the distance is a little. As a guide, it may be within ± 20%, preferably within ± 10%.
[0288]
The Fresnel lens 552 is formed by processing acrylic or polycarbonate resin. As an example, a product sold by Koyo Co., Ltd. can be used. When the Fresnel lens 552 is small, it can be manufactured using a machine tool. However, when it is manufactured in large quantities, it is easier to manufacture it using a mold, and the cost can be reduced. Although the Fresnel lens 552 has a flat surface facing the lamp 11, the reflectivity is reduced, and this is to increase the amount of light incident on the Fresnel lens 552. Also, it is to satisfy the sine condition.
[0289]
In FIG. 83, the light collecting means is constituted by using one Fresnel lens 552, but it is needless to say that the light collecting means may be constituted by using a plurality of Fresnel lenses 552. Further, a Fresnel lens 552 and a plano-convex lens may be combined. The configuration shown in FIG. 60 may be used. FIG. 59A shows a configuration in which the light incident surface of the Fresnel lens 552a is concave. By forming such a concave surface, the angle of light incident on the lens becomes relatively small, and the reflected light decreases.
[0290]
In the description of the viewfinder of the reference example related to the present invention, substantially parallel light is made incident on the liquid crystal display panel 1333, but the present invention is not limited to this. For example, in the case of the light ray 51b in FIG. 57, the principal ray incident on the liquid crystal display panel 1333 is oblique, but even if it is slightly oblique, practical use does not hinder.
[0291]
The diffusion plate 15 is disposed between the liquid crystal display panel 1333 and the Fresnel lens 552 so that the groove of the Fresnel lens 552 can be seen through the magnifying lens 1336. However, the part that can be seen particularly well (will be seen) is the central part of the Fresnel lens 552 (the area shown by 921 in FIG. 92). The outer peripheral portion of the Fresnel lens 552 is hardly visible. Therefore, as shown in FIG. 92B, a diffusion portion 921 is formed at the center of the Fresnel lens 552. Specifically, the diffusion portion 921 corresponds to, for example, one obtained by reducing the size of the diffusion plate 15. In addition, it is also effective to apply the technical idea of FIG.
[0292]
The diffusion plate 15 is an optical low-pass filter, and is a concept including a diffraction grating, a prism sheet, a microlens array, a cell hook lens array, and the like in addition to the diffusion plate described above. Furthermore, a method using the following MTF concept without using a low-pass filter such as a diffusion plate is also included.
[0293]
The diffusion plate 15 deteriorates the directivity of the light emitted from the light collecting means (Fresnel lens, light collecting lens 522), and lowers the display brightness of the liquid crystal display panel 1333. Therefore, MTF (Modulation Transmission Function) may be considered as one method of a configuration that does not require the diffusion plate 15. The description is shown in FIG. Normally, the magnifying lens 1336 is focused on the light modulation layer of the liquid crystal display panel 1333 (the focus is adjusted so that the virtual image of the light modulation layer can be seen well. Adjust the position of the magnifying lens 1336 as described above). Here, the position (distance) at which focus is achieved is f. If the distance between the magnifying lens 1336 and the Fresnel lens 552 is f, the groove of the Fresnel lens 552 is in focus. Conversely, if the distance between the magnifying lens 1336 and the Fresnel lens 552 is different from f, the groove of the Fresnel lens 552 becomes out of focus and cannot be seen by the observer.
[0294]
In the optical field, MTF is used as a comparison regarding imaging. For example, although the expression is a bit rough, when the MTF is 100%, the image is in focus at an infinite resolution. The smaller the MTF, the more out of focus. As shown in FIG. 94, various MTFs can be created depending on the configuration and design of the optical system. In FIG. 94, a distance of 0 means that the distance between the magnifying lens 1336 and the modulation layer of the liquid crystal display panel 1333 is f (focus is on). The resolution degrades as it deviates from that.
[0295]
According to the optical design, it is possible to realize a configuration in which the MTF deteriorates abruptly when the focus deviates slightly from the point of focus (dotted line in FIG. 94), and a configuration in which the MTF does not deteriorate even if the focus is far away (solid line in FIG. 94). In the view finder of the reference example related to the present invention, it is preferable that the configuration is indicated by a dotted line in FIG.
[0296]
That is, the Fresnel lens 552 is placed at a position where the MTF is 20% or less. In the case of the solid line, if the point where the MTF is 20% or less is X2, the total length of the viewfinder becomes long. Preferably, Fresnel lens 552 is arranged at a position where the MTF is 10% or less.
[0297]
By arranging the Fresnel lens 552 at a position where the MTF decreases as described above, the MTF (resolution) of the groove of the Fresnel lens 552 decreases and the groove becomes invisible, so that the diffusion plate 15 is not required. In addition, the fact that the groove of the Fresnel lens 552 becomes invisible means that light passing through the groove position has no periodicity when it reaches the liquid crystal display panel, so that moire hardly occurs.
[0298]
As an example, the diameter of the Fresnel lens 552 used in the viewfinder of the reference example related to the present invention is 20 mm, and the focal length is 22 mm. As the focal length d decreases, the distance d between the light emitting element (lamp 11) and the Fresnel lens 552 can be shortened and the viewfinder can be made compact, but the light collecting efficiency of the Fresnel lens 552 decreases. Conversely, if the focal length d is too long, the light focusing efficiency will be improved, but the total length of the viewfinder will be too long. In that case, two Fresnel lenses should be used. Then the focal length can be shortened.
[0299]
The focal length d of the Fresnel lens 552 is determined according to the diagonal length dp of the effective display area of the liquid crystal display panel 1333. The focal length is set to 0.6 times or more and 2.0 times or less of dp, and more preferably 0.8 times to 1.5 times of dp.
[0300]
The viewfinder should have a certain length (total length) from the viewpoint of ease of use when used, but it is desirable that the viewfinder be as short as possible (compact) when it is carried. Therefore, in the reference example related to the present invention, the distance d2 between the liquid crystal display panel 1333 and the Fresnel lens 552 and the distance d1 between the Fresnel lens 552 and the lamp 11 can be reduced. Therefore, the Fresnel lens 552 is attached to the body 1321b, and the lamp 11 and the like are attached to the body 1321c. FIG. 84 is a configuration diagram when contracted. A spring or the like (not shown) is arranged between A and B in FIG. 83, and can switch between the extended state in FIG. 83 and the contracted state in FIG. In particular, since the Fresnel lens 552 is flat, it is easy to contract.
[0301]
In FIG. 83, both d1 and d2 can be contracted. However, it is needless to say that a configuration in which only one of them can be contracted as shown in FIG. The concave lens 1336b is a lens for correcting aberration and color, and is preferably applied to the viewfinder having the configuration shown in FIG. Further, the concave lens 1336b may be a convex lens.
[0302]
In the viewfinder, since the position of the pupil of the observer is almost fixed by the eyepiece cover 1332, the light source disposed behind the viewfinder may have narrow directivity. In a conventional viewfinder using a light box 1331 (FIG. 137) using a fluorescent tube as a light source, only light that travels within a small solid angle in a certain direction from an area almost as large as the display area of the liquid crystal display panel 1333 is used. And light traveling in other directions is not used. That is, the light use efficiency is very poor.
[0303]
In the reference example related to the present invention, a light source 11 having a small luminous body is used, and light emitted from the luminous body at a wide solid angle is converted into near parallel light by a Fresnel lens 552 or the like. In this case, the directivity of the emitted light from the Fresnel lens 552 and the like becomes narrow. If the observer's viewpoint is fixed, the light having the narrow directivity described above is sufficient for use in a viewfinder. If the size of the light emitting body is small, the power consumption is naturally small. As described above, the viewfinder of the reference example related to the present invention utilizes the fact that the observer views the display image while fixing the viewpoint.
[0304]
FIG. 85 shows a configuration in which the viewfinder of FIG. 83 is attached to a video camera body 431. When the viewfinder is used, it is stored in the video camera body 431 in a state where it is contracted by the fasteners 851 (projections) (see FIG. 85A). When the viewfinder is used, the fixing by the fasteners 851 is released (FIG. 83), and the portions A and B shown in FIG. 83 are extended, so that the parallel light is appropriately irradiated on the liquid crystal display panel 1333 by the lamp 11.
[0305]
However, as shown in FIG. 83, if there is no contraction mechanism between the Fresnel lens 552 and the lamp 11, the distance d1 cannot be shortened and the total length of the viewfinder becomes longer. In that case, as shown in FIG. 81, a mirror 751 may be arranged between the lamp 11 and the Fresnel lens 552 to bend the optical path. The protruding portion (insertion portion 811) in FIG. 81 does not hinder at all if it is designed or configured to be inserted into the video camera body 431 having the imaging lens 432 (see FIG. 81 (b)). In other words, it is possible to freely rotate in the direction in which the observer looks at the insertion portion 811 as an axis (see the dotted line in FIG. 81 (b)).
[0306]
The TN liquid crystal display panel 1333 requires a polarizing plate 1334 to perform light modulation. In order to obtain the optimum display contrast, it is necessary to adjust the polarization axis angle between the polarizer 1334a and the analyzer 1334b. The angle has a relationship with the voltage applied to the liquid crystal layer of the liquid crystal display panel 1333, and it is often necessary to adjust the angle according to the characteristics of each liquid crystal display panel. As shown in FIG. 82, the knob 821 is connected to the Fresnel lens 552. That is, when the knob 821 is moved up and down, the Fresnel lens 552 rotates and the polarization axis of the polarizer 1334a also rotates. Therefore, the polarization axis can be easily adjusted according to the characteristics of the individual liquid crystal display panel 1333.
The configuration of FIG. 81 is a configuration that facilitates the adjustment. A polarizer 1334a is attached to the Fresnel lens 552. The polarizer 1334a is configured to be rotatable around the lens center. That is, by rotating the Fresnel lens 522, the polarization axis of the polarizer 1334a also rotates, and the angle between the polarization axis of the polarizer 1334a and the analyzer 1334b can be adjusted. By adjusting the angle, the image is adjusted to a position where the image on the display panel 1333 is best viewed.
[0307]
Part of the light emitted from the lamp 11 is reflected by the Fresnel lens 552 or the like and becomes stray light. In order to prevent the stray light, an antireflection film may be formed on the Fresnel lens 552 or the like. However, even if an antireflection film is formed, generation of stray light cannot be completely prevented.
[0308]
The stray light causes a reduction in the contrast of the displayed image. In order to avoid this problem, a circular stop 931 may be arranged between the lamp 11 and the Fresnel lens 552 as shown in FIG. The circular aperture 931 has a circular window at the center, and a plurality of apertures are arranged concentrically at predetermined intervals. The circular stop 931 allows light emitted from the lamp 11 to pass through only light that directly enters the effective area of the Fresnel lens 552. The inner surfaces of the body 1321 and the eyepiece ring 1335 are black or dark to prevent light reflection. Of the light emitted from the lamp 11, unnecessary light is absorbed by the light-shielding portion of the circular stop 931, and light slightly reflected without being absorbed is absorbed by the light-shielding portion of the other stop or the inner surface of the body 1321. Therefore, the light does not enter the Fresnel lens 552. Therefore, the decrease in the contrast of the displayed image due to unnecessary light incident on the liquid crystal display panel 1333 is extremely small. The number of apertures may be one, but the greater the number, the greater the effect.
[0309]
The liquid crystal display panel 1333 usually has a black matrix (not shown). The black matrix is used to make movement of liquid crystal on a signal line of the liquid crystal display panel 1333 invisible, and / or to shield light to a thin film transistor which switches a pixel. However, when the number of pixels of the liquid crystal display panel 1333 is small, the black matrix is conspicuous and the image quality is reduced. Therefore, as shown in FIG. 93, by disposing a diffraction grating 932 as an optical low-pass filter between the liquid crystal display panel 1333 and the pupil of the observer, the black matrix can be made inconspicuous. The diffraction grating 932 is disposed between the magnifying lens 1336 and the liquid crystal display panel 1333. Further, it may be arranged on the incident light side of the liquid crystal display panel 1333. However, it is needless to say that the pitch, height, and the like of the diffraction grating 932 need to be changed depending on the arrangement position. The diffraction grating 932 has an effect of making the black matrix difficult to see. Therefore, a smooth display image can be obtained without seeing the black matrix.
[0310]
The diffraction grating 932 is of a transmission type, and the cross-sectional shape of the grating may be a sine curve, an arc, a trapezoid, or the like. Many deformations such as one-dimensional and two-dimensional patterns can be considered for the pattern of the diffraction grating 932. When the size of the pixel of the liquid crystal display panel 1333 is 100 to 30 μm and the diffraction grating 932 is arranged near the liquid crystal display panel 1333, the pitch is appropriately in the range of 100 to 20 μm.
[0311]
Further, when the diffraction grating 932 is arranged near the magnifying lens 1336, 2 to 0.1 mm is appropriate. As a method for manufacturing the diffraction grating 932, a method in which an inorganic substance such as SiO 2 is deposited on a glass substrate and patterned, a method in which a mixture of a polymer and a dopant is spin-coated on the glass substrate, exposed to light through a pattern mask, and There is a method of sublimating the dopant by heating. Kuraray Co., Ltd. also manufactures and sells diffraction grating plates.
[0312]
Further, the diffusion plate 15 may be attached to the liquid crystal display panel 1333 as shown in FIG. By attaching the liquid crystal display panel 1333 to the mounting holder 991 and attaching the lamp 11 to the body 1321, the entire length of the viewfinder can be contracted and extended as shown in FIGS.
[0313]
As a problem of the Fresnel lens 552, there is interface reflection occurring in the Fresnel lens 552 as shown in FIG. In particular, when the incident light 872 enters the interface 1022 of the Fresnel lens 552, it is reflected at the interfaces 1024, 1023, etc. as shown by the dotted line in the figure. As a countermeasure, there is a method of increasing the thickness t of the Fresnel lens 552 as shown in FIG. When it is physically difficult to increase the thickness of the Fresnel lens 552 itself, the transparent substrate 1011 may be attached to the Fresnel lens 552 with a transparent resin 901. A light absorbing film 1012 is applied to a side surface of the transparent substrate or the like (outside the effective display range, a region where light does not directly enter). As the light absorbing film 1012, a black paint or the like is exemplified.
[0314]
By making the Fresnel lens 552 seem thicker as described above, the ray 872 is reflected once at the interface 1031 and enters the side black paint 1012 as shown in FIG. 103, so that no halation occurs in the Fresnel lens 552. In FIG. 101, if the relationship between t and d is d / 8 <t, halation hardly occurs and good results were obtained.
[0315]
If the PD liquid crystal display panel 1041 is used instead of the diffusion plate 15, the degree of diffusion can be freely changed. FIG. 104 illustrates this configuration.
First, the PD liquid crystal display panel 1041 used in place of the diffusion plate 15 will be described. As described above, the PD liquid crystal display panel 1041 operates according to the operation principle shown in FIG. An ITO electrode 1046 is formed on the glass substrate 1045, and a PD liquid crystal layer 1047 is sandwiched between the ITO electrodes 1046. Note that reference numeral 1044 denotes a sealing resin. When no voltage is applied to the ITO electrode 1046, the liquid crystal layer 1047 is in a scattering state, and when a voltage is applied, the PD liquid crystal layer 1047 is in a transparent state. The degree of diffusion of the PD liquid crystal layer 1047 changes depending on the level of the voltage.
[0316]
The signal generation source 1042 outputs a rectangular wave, and the rectangular wave changes a signal amplitude by a signal amplitude variable device 1043. The signal amplitude is varied by the resistor Rb. The larger the size of the rectangular wave, the more transparent the PD liquid crystal layer 1047 becomes.
[0317]
Light 51 emitted from lamp 11 is collected by Fresnel lens 552. The straightness of the light is changed by the PD liquid crystal display panel 1041. Therefore, the PD liquid crystal display panel 1041 has an effect of making the groove of the Fresnel lens 552 difficult to see like the diffusion plate 15. Further, since the light transmittance is changed, the display brightness of the display panel 1333 can be adjusted.
[0318]
When the transmittance of the PD liquid crystal display panel 1041 is high, the liquid crystal display panel 1333 can perform high-luminance display. Therefore, it is suitable for viewing a display image in a bright place. Conversely, when the transmittance of the PD liquid crystal display panel 1041 is low, the display image on the liquid crystal display panel 1333 is dark. However, since the viewing angle is wide, it is suitable for viewing the liquid crystal display panel 1333 from a wide range. As described above, the display state of the liquid crystal display panel 1333 can be adjusted according to the situation.
[0319]
In order to prevent light reflection by the interface, the diffusion plate 15 and the Fresnel lens 552 may be glued together with an optical binder as shown in FIG. Light transmittance is increased, and halation at the interface is also reduced. Needless to say, the case where the PD liquid crystal display panel 1041 is used instead of the diffusion plate 15 may be as shown in FIG. Of course, as shown in FIG. 106, both the diffusion plate 15 and the PD liquid crystal display panel 1041 may be used.
[0320]
As described above, needless to say, even if a diffraction grating 932 is used instead of the diffusion plate 15 as shown in FIG. 107, the function as a diffusion plate can be achieved. Also, in order to change the radiation area of the light from the lamp 11, a stop 1091 is provided as shown in FIG. The aperture 1091 is exemplified by an aperture used for a shutter rainbow aperture, aperture, etc. of a camera. As the hole diameter of the aperture 1091 is reduced, the directivity is narrowed, and the display contrast of the liquid crystal display panel 1333 is improved. Conversely, when the value is increased, the directivity is widened and the display contrast of the liquid crystal display panel 1333 is reduced, but the displayed image is bright.
[0321]
Although the configuration of the viewfinder of the reference example related to the present invention has been described as including the magnifying lens 1336, the configuration is not limited to this. For example, as shown in FIG. 110, the magnifying lens 1336 may not be provided. In this case, the display image that can be viewed by the observer is small, but there is no practical problem when the size of the liquid crystal display panel 1333 is equal to or more than a certain value (1 inch or more is easy to see).
[0322]
Although the Fresnel lens 552 and the like have been described as a transmission type, it goes without saying that a reflection type can be configured as shown in FIG. The reflection type Fresnel lens 1211 can be manufactured by processing an aluminum plate or the like. Alternatively, it can be manufactured by molding with a glass resin and depositing a metal thin film such as Al on the surface. The Fresnel lens 1211 condenses the light reflected from the lamp 11 and the reflection plate 883 and converts the light into substantially parallel light to illuminate the liquid crystal display panel 1333.
[0323]
As shown in FIG. 111, light from the lamp 11 can be applied to a light condensing means (Fresnel lens, illumination lens 552, etc.) using a light guide 1111. Thus, if the light guide 1111 is used, there is no restriction on the arrangement position of the lamp 11. Therefore, the lamp 11 is placed in a small space, and the space can be effectively used.
[0324]
As shown in FIG. 112, a reflective film 1121 made of Al or the like is formed on the outer surface of the light guide 1111, and the light guide 1111 is covered by the lamp 11. Light emitted from the lamp 11 is transmitted through the light guide 1111 while being reflected between the reflection films 1121, and emitted from the emission end.
[0325]
In FIG. 112, the light guide 1111 is placed over the lamp 11, but the present invention is not limited to this. The light guide 1111 may be attached to the tip of the lamp 11 with an adhesive 1051 as shown in FIG. Further, as shown in FIG. 113 (b), a spring in which a plurality of optical fibers 1131 are springed may be used as a light guide.
[0326]
FIG. 114 illustrates a method in which the liquid crystal display panel 1333 is illuminated with external light (such as sunlight 1141) particularly when outdoors. A window is opened at the top of the body 1321 of the viewfinder, and a Fresnel lens 1143 is fitted therein. The Fresnel lens 1143 is used to reduce the thickness of the lens, and may be replaced with a plastic or glass positive lens when permitted. Since the sunlight 1141 is almost parallel light, the light is condensed by the Fresnel lens 1143, reflected by the mirror 751, the traveling direction of the light is bent, and is incident on the condensing means 552.
[0327]
That is, the Fresnel lens 552 has a function of condensing both the outdoor light 1141 and the light from the lamp 11.
[0328]
The state of the light reflected by the mirror 751 is arranged at a position that is similar to the state of the light emitted from the lamp 11. Naturally, when illuminating the liquid crystal display panel 1333 without taking the outdoor light 1141 into the body 1321, the lamp 11 is caused to emit light and the light from the lamp 11 is used.
[0329]
When the lamp 11 is made to emit light or when the outdoor light 1141 is weak, the lamp 11 is made to emit light in an auxiliary manner, and the amount of light flux (luminance) per unit area incident on the display panel 1333 is used at a constant value. Whether the lamp 11 is turned on or the brightness of the emitted light is determined by determining the intensity of the outdoor light 1141 by a photo sensor 1142 disposed at the top of the body 1321 or the like. FIG. 115 shows a circuit configuration for making this determination. A photodiode or the like corresponds to the photo sensor 1142.
[0330]
The light detection circuit 1152 includes a photo sensor 1142 and an operational amplifier A.₁And the like. Operational amplifier A₁Outputs a voltage V according to the intensity of the outdoor light 1141. Reference numeral 1151 denotes a hysteresis comparator circuit, which includes a resistor R that determines a hysteresis state.₂, R₃And operational amplifier A₂And reference voltage V₅From a voltage source that generates
[0331]
Operational amplifier A₁Output voltage V is the reference voltage V₅Is compared to When V is over a certain value, operational amplifier A₂The voltage at the output terminal a becomes + voltage (or-voltage). The contact of the analog switch SW1153 is closed by the voltage, and the voltage E_aIs applied to the anode electrode 25, and the lamp 11 is turned on. Conversely, operational amplifier A₂The analog switch SW1153 is open at the point where the output is negative voltage (or positive voltage).
[0332]
The reason why the hysteresis comparator circuit 1151 is used is to cope with the case where the intensity of the light 1141 input to the photosensor 1142 is changed (for example, when the sun enters a cloud shadow while using a video camera). Comparator A each time depending on the intensity of external light₂Is changed, the lamp 11 blinks, and the display image on the liquid crystal display panel 1333 is very difficult to see. By using the hysteresis comparator circuit 1151, once the lamp 11 is turned on, it does not turn off even if the outdoor light 1141a becomes strong. Therefore, it does not blink.
[0333]
FIG. 117 is a configuration diagram of a viewfinder using a liquid crystal display panel 1333 having a larger display screen than that of FIG. The lamp 11 is placed horizontally to shorten the entire length of the viewfinder. Although the light-shielding cover 1171 and the liquid crystal display panel 1333 are illustrated separately for easy understanding, they are actually arranged in close contact with each other. The light-shielding cover 1171 is used to define the direction in which the observer views. If the observer tries to look at the liquid crystal display panel 1333 from an oblique direction, the light-shielding cover 1171 makes the periphery of the display screen of the liquid crystal display panel 1333 invisible.
[0334]
Therefore, the observer tries to see the display image on the liquid crystal display panel 1333 from the front of the screen. The reason for disposing the eyepiece cover 1333 in this way is that the light emitted from the lamp 11 is converted into light having a narrow directivity by the Fresnel lens 552 (or a condensing lens), and the observer can see the light having the narrow directivity. Because it becomes. Since the directivity is narrow, the image suddenly looks dark except for the front of the liquid crystal display panel 1333. Therefore, the light-shielding cover 1171 is arranged to guide the observer to view the display image from a direction in which the display image looks bright.
[0335]
However, the viewing angle is enlarged by disposing the diffusion plate 15. The higher the degree of diffusion of the diffusion plate 15, the wider the viewing angle (the angle until the display image becomes invisible depending on the viewing angle). However, the displayed image becomes dark, and the display contrast also decreases. Therefore, the degree of diffusion of the diffusion plate 15 is made as low as possible. Therefore, the angle at which the display image can be viewed well is forcibly defined by using the light shielding cover 1171. With this configuration, light emitted from the light source can be effectively used, and power consumption can be reduced.
[0336]
When the effective display area of the liquid crystal display panel 1333 is large, or when the focal length of the Fresnel lens 552 is long, the entire length may be long. Therefore, as shown in FIG. 118, the optical path 872 is bent using a mirror 751. What is necessary is just to comprise. The light emitted from the lamp 11 is bent at an angle by the mirror 751b and enters the Fresnel lens 552.
[0337]
FIG. 117 illustrates that the small fluorescent discharge tube 11 is used as the light emitting element (lamp 11). However, the light emitting element may be a small fluorescent tube 882 or the like as shown in FIG. Examples of the small fluorescent tubes 882 include K-C21T26E85H and K-C30T26E85H manufactured by Matsushita Electric Industrial Co., Ltd. These fluorescent tubes are of the cold cathode type, and the lamp power consumption is as low as 0.33 W or 0.4 W. A semi-cylindrical reflector 883 is arranged on the back of the fluorescent tube 882 so that the light emitted from the fluorescent tube 882 can be effectively emitted to the front. In addition, a plate-like cylindrical lens 881 is disposed to satisfactorily condense light from the fluorescent tube 882. This is because the light-emitting means is a rod-shaped light-emitting body, and does not need to be the concentric Fresnel lens 552, and may be a cylindrical lens 881.
[0338]
Light emitted from the front surface of the fluorescent tube 882 directly enters the cylindrical lens 881, is collected, and enters the liquid crystal display panel 1333. Light emitted from the rear surface of the fluorescent tube 882 is reflected by the reflector 833, then enters the cylindrical lens 881, and enters the liquid crystal display panel 1333. Of course, the light shielding cover 1171 may be arranged as shown in FIG.
[0339]
In FIG. 83, the distance d2 between the liquid crystal display panel 1333 and the Fresnel lens 552 is configured to be extended when used. The same can be implemented with the configuration of FIG. As shown in FIG. 87, the case 861 to which the liquid crystal display panel 1333b is attached and the case 871 to which the lamp 11 is attached are connected by bellows 862b, and the bellows 862b is extended and contracted to adjust the distance between the display panel 1333 and the Fresnel lens 552. You should be able to do it.
[0340]
In the configuration of FIG. 87, since the liquid crystal display panel 1333 is large, a certain distance is required between the lamp 11 and the condenser lens 552, so that the volume is large. In order to solve this, a configuration as shown in FIG. 86 may be used. When the viewfinder is not used, the bellows 862a is folded up as shown in FIG. 86 (a). In use, the bellows 862a and 862b are extended as shown in FIG. 86 (b) so that the light emitting portion of the lamp 11 comes to the focal position of the condenser lens 552.
[0341]
The liquid crystal display panel 1333, the diffusion plate 15, and the condenser lens 552 are integrally fixed via bellows 862. The bellows 862 is used for preventing external light from entering and for contracting, etc., and is not limited to this. For example, as shown in FIG. 83, it may be a tubular shape (1321b) that can be extended and contracted.
[0342]
It is easy for the observer to adjust the display image on the liquid crystal display panel 1333 in a direction that makes it easy to see. Screws are fixed to the rotation shaft 863 so as to be rotatable, and can be freely rotated and fixed as indicated by the dotted and solid lines in FIG. 86 (b). It is particularly effective when used as a monitor of a video camera. This is because it is necessary to change the viewing position of the viewfinder in order to properly shoot (image) the subject with the video camera.
[0343]
In order to effectively use the light radiated from the apex or side surface of the lamp 11, a configuration as shown in FIG. 119 may be used. Light 872 emitted from the apex of the lamp 11 is reflected by the mirror 883a like the light 872d in FIG. 120B and travels toward the display panel 1333. Of course, the light 872 emitted from the front surface goes straight to the display panel 1333. Light emitted from the side surface of the lamp 11 is reflected by mirrors 883c and 883b and enters the display panel 1333 as shown in FIG. As shown in FIG. 120, the light from the oblique direction is incident on the display panel 1333 using the mirror 883, so that the viewing angle when the observer views the display image on the display panel 1333 is widened. That is, even if the position of the eyes is slightly shifted, the displayed image does not suddenly become dark.
[0344]
As shown in FIG. 123, a plurality of light emitting elements such as lamps 11a and 11b are used, and the light emitted from each light emitting element is obliquely incident on the liquid crystal display panel 1333 (light rays 1232a and 1232b) to increase the viewing angle. Can be. Therefore, in the viewfinder of the reference example related to the present invention, the number of the light emitting elements (the lamps 11) is not limited to one. This is because the use of a plurality of light emitting elements has the effect of widening the viewing angle and making it easier to see the displayed image.
[0345]
The view finder of the reference example related to the present invention described above was constituted by one liquid crystal display panel 1333. However, the viewfinder according to the present invention is not limited to this, and includes, for example, the viewfinder of FIG.
[0346]
In FIG. 95, reference numeral 952 denotes a PBS (polarizing beam splitter), which is sold by a number of optical manufacturers (for example, 03PBS025 by Meles Griot Japan). A dielectric thin film is laminated on the light combining surface 951 of the PBS 952 and reflects or transmits P-polarized light or S-polarized light.
[0347]
The light modulated by the liquid crystal display panel 1333a is reflected by the light combining surface 951 of the PBS 952 (P-polarized or S-polarized) and enters the magnifying lens 1336. On the other hand, the light modulated by the liquid crystal display panel 1333b passes through the light combining surface 951 of the PBS 952 (S-polarized light or P-polarized light) and enters the magnifying lens 1336. Since the observer superimposes the images on the two liquid crystal display panels 1336, the number of pixels is doubled. Therefore, high definition display can be realized. Note that a half mirror that transmits half of the light may be used instead of the PBS 952.
[0348]
When a half mirror is used, light emitted from the lamp 11a is incident on the liquid crystal display panel 1333a, and light emitted from the liquid crystal display panel 1333a is a half mirror (the PBS 952 in FIG. 95 may be replaced with a half mirror). ). The half mirror reflects half of the light to the magnifying lens 1336 side. On the other hand, light emitted from the lamp 11b is incident on the liquid crystal display panel 1333b, and light emitted from the liquid crystal display panel 1333b is incident on the half mirror. The half mirror similarly reflects half of the light to the magnifying lens 1336 side. The optical image of the liquid crystal display panel 1333a and the optical image of the liquid crystal display panel 1333b are shifted from each other by a half pixel to superimpose the two optical images.
[0349]
Since the liquid crystal display panel has a black matrix formed thereon, the optical image of the pixel of the other liquid crystal display panel 1333b is superimposed on the optical image of the black matrix of one liquid crystal display panel 1333a. By superimposing as described above, the definition of the displayed image is improved. It goes without saying that the sampling timing of the video signals of the two liquid crystal display panels is shifted by half a pixel.
[0350]
Similarly, a case where the number of the liquid crystal display panels 1333 is three or more can be considered. FIG. 116 shows the configuration. 953 is a dichroic mirror. Assuming that the lamp 11a emits red light, the light from the lamp enters the liquid crystal display panel 1333a. It is assumed that a red video signal is applied to the liquid crystal display panel 1333a. The red light modulated by the liquid crystal display panel 1333a is reflected by the dichroic mirror 953a and enters the magnifying lens 1336. It is assumed that the lamp 11b emits green light and a green image signal is applied to the liquid crystal display panel 1333b. The green light modulated by the liquid crystal display panel 1333b passes through a dichroic mirror 953 and enters a magnifying lens 1336. The lamp 11c emits blue light, and the liquid crystal display panel 1333c is applied with a blue video signal. The blue light modulated by the liquid crystal display panel 1333c is reflected by the dichroic mirror 953a and enters the magnifying lens 1336. An observer (not shown) sees an image modulated by the three liquid crystal display panels 1333 and synthesized by the dichroic mirror 953. Therefore, the number of pixels is three times as large as that of one liquid crystal display panel 1333, and high-definition image display can be realized.
[0351]
In FIG. 120, the configuration for improving the viewing angle using two lamps 11 has been described. However, there is a method of adjusting the viewing angle in an appropriate direction with one lamp 11. This method will be described with reference to FIG. The viewing angle may be set in a direction that is most visible to the observer. To adjust the viewing angle, the center of the lens 552 may be changed from the center axis 961 of the lamp 11 and the liquid crystal display panel 1333. In other words, if the center axis is shifted, the angle of the principal ray incident on the liquid crystal display panel 1333 becomes hard. Therefore, the position of the Fresnel lens 552 may be shifted by x, or the position of the lamp 11 may be slightly shifted from the center axis 961. By shifting the position, the observer can be adjusted to a position where the display image on the liquid crystal display panel 1333 can be optimally viewed. By applying this technical idea to the view finder of the reference example related to the present invention, the observer can easily adjust to the optimal viewing direction.
[0352]
The above can be applied not only to the viewfinder but also to a display area 971 attached to a telephone, for example. FIGS. 97 and 98 show the explanatory diagrams. The telephone number or the like of the other party is displayed in the display area 971 of the telephone, and the display is not desired to be seen by other persons for security. The display device including the lamp 11, the condenser lens 552, and the display panel 1333 according to the reference example related to the present invention has a narrow viewing angle (viewing angle) at which a display image can be viewed. Therefore, it is visible only to the person making the call, and is effective in security. However, since the viewing angle is narrow, the person using the telephone cannot see the display image in the display area 971 unless the principal ray is directed in the optimal direction. For example, in the case of FIG. 98, when the direction of the chief ray is a, the observer A can see the display image but cannot see the observer B who is shorter than it. Therefore, by moving the position of the lamp 11 or the position of the condenser lens 552 in the direction of the arrow, only the observer B (the telephone user) can be seen.
[0353]
Adjustment of the position of the condenser lens 552 and the like can of course be performed automatically. When the user picks up the receiver 974 or presses the push button, the user is approaching the telephone body 973. At that time, infrared rays are generated from infrared LEDs 975a to 975d (see FIG. 97 (b)) attached to the telephone main body 973, and the light reflected by the user is detected by the light receiving element 976. Through the above operation, the outline of the user's height and the like can be known. If the height of the back is known, the condenser lens 552 may be moved by a moving amount x set in advance with respect to the height of the back.
[0354]
The technical idea of using the Fresnel lens 552 and the diffusion sheet 15 described with reference to FIG. 83 does not apply only to the viewfinder, but can also be applied to a projection display device as shown in FIG. The metal halide lamp 1221a corresponds to the light emitting means, and the illumination optical system 1221 is configured by the concave mirror 1221b and the UVIR cut filter 1221c. The Fresnel lens 552 converts the light from the illumination optical system 1221 into substantially parallel light and makes the light enter the liquid crystal display panel 1333. This is for preventing the grooves of the diffusion sheet 15 and the Fresnel lens 552 from being projected on a screen (not shown). The projection lens 1222 enlarges and projects the modulated image of the liquid crystal display panel 1333 on a screen.
[0355]
FIG. 122A shows an example in which a liquid crystal display panel 1333 is provided with a color filter 1223 to perform color display. Even without the color filter 1223, a color image can be displayed with the configuration of FIG. The white light emitted from the illumination optical system 1221 is separated by the dichroic mirror 953 into three lights of blue, green, and red. A micro lens array 1224 in which micro lenses 1225 are arranged in a matrix is attached to the liquid crystal display panel 1333. One micro lens 1225 corresponds to three pixels 244 (one set of three of blue, green, and red). The blue light enters the pixel 244b by the micro lens 1224, the green light enters the pixel 244b, and the red light enters the pixel 244c. Therefore, color display can be performed without the color filter 1223.
[0356]
The technical idea of the present embodiment can be applied to other devices. For example, the present invention can be applied to a stereoscopic display device without glasses (3D display system) shown in FIG. An image splitter 1231 is correctly aligned with each pixel of the liquid crystal display panel 1333. Each of the light emitting elements (lamp 11a, 11b) is provided with a reflection mirror 833a or 833b, and emits light toward the Fresnel lens 552. Each light emitting element is disposed at a substantially focal position of the Fresnel lens 552.
[0357]
The principal ray 1232a of the lamp 11a is inclined at an angle + θ with respect to the normal of the Fresnel lens 552 (or the liquid crystal display panel 1333). On the other hand, the principal ray 1232b of the lamp 11b is inclined by -θ with respect to the normal of the Fresnel lens 552 (or the liquid crystal display panel 1333). The image splitter 1231 has openings 1241 and light shielding portions 1242 formed alternately (see FIG. 124). The light shielding portion 1242 has a matrix shape or a stripe shape.
[0358]
FIG. 124 is an explanatory diagram of the 3D display system of the present embodiment. Light from the lamp 11 enters the liquid crystal display panel 1333. The chief ray 1232a mainly passes through the pixels of the right-eye image 1244, and the chief ray 1232b passes through the pixels of the left-eye image 1243. The light blocking portion 1242 of the image splitter 1231 prevents light passing through the pixels of the right-eye image 1244 from reaching the left eye of the observer 1245 and light reaching the pixels of the left-eye image 1243 reaches the right eye. Has a function to prevent. Also, the opening 1241 of the image splitter 1231 allows light passing through the pixels of the left-eye image 1243 to reach the left eye of the observer 1245 and light passing through the pixels of the right-eye image 1244 to the right eye. It has a function to make it reach. Naturally, the liquid crystal display panel 1333 displays the image for the left eye on the pixel of the left eye image 1243 and the image for the right eye on the pixel of the right eye image. This can be realized by switching the video signal for the right eye and the video signal for the left eye for each pixel with an analog switch or the like and forming one video signal to be input to the liquid crystal display panel 1333.
[0359]
In FIG. 124, a small fluorescent discharge tube is used as the light emitting element. However, as shown in FIG. 52, a flat fluorescent lamp 521 (for example, Ushio Electric Co., Ltd. product number UFU07E852) can be used as the light emitting element (see FIG. 125). Further, the LED shown in FIG. 51 can be used. As shown in FIG. 125, a booster coil 1251 is connected to the back surface of the flat fluorescent lamp 521. The number of light emitting elements may be one. Further, instead of the Fresnel lens 552, a convex lens 1252 made of plastic or the like may be used. This is because the light collecting function is the same. The convex lens directs a flat surface or a surface having a large radius of curvature toward the flat fluorescent lamp 521. This is because the sine condition is easily satisfied, and the luminance uniformity of the display image on the liquid crystal display panel 1333 is improved.
[0360]
However, the convex lens is not limited to a plano-convex lens, and may be a biconvex lens. A lenticular screen (lens) may be used as the image splitter 1231 in FIG. This is because a lenticular screen is formed with a semi-cylindrical lens, and the lens can be selectively controlled between transmitted light for the left eye and transmitted light for the right eye. For example, a configuration in which a lenticular lens (lenticular screen) is added to the liquid crystal display panel 1333 is illustrated in FIG. 127.
[0361]
In FIG. 123, light for the left eye and light for the right eye are separated using the image splitter 1231. The same function can be realized by using a prism plate 1341 as shown in FIG. The prism plate 1341 is a triangular plate.
[0362]
Light having a narrow directivity emitted from the light condensing means 1252 enters the prism plate 1341 and changes the traveling direction of the light according to Snell's law. Two adjacent pixel electrodes 244 correspond to the triangle of one prism plate 1341. The “dotted line” light passing through the prism plate 1341 passes through a pixel 244b that displays an image for the right eye. On the other hand, the “solid line” light beam passes through the pixel 244a that displays the image for the left eye. Accordingly, light for the right eye and light for the left eye are formed by the prism plate 1341, and the active matrix type liquid crystal display panel 1333 alternately displays the right eye and the left eye for each pixel so that the observer can view a stereoscopic image. (3D) You can see the display.
[0363]
If the triangular joint of the prism plate 1341 is conspicuous, a scattering means (diffusion plate 15) may be arranged between the prism plate 1341 and the liquid crystal display panel 1333 or on the light emission side of the liquid crystal display panel 1333. Therefore, the technical idea of using the diffusion plate 15 for the viewfinder is utilized in 3D.
[0364]
In FIG. 134 and the like, light for the right eye and light for the left eye are formed using the prism plate 1341. In addition, it can be realized by the method shown in FIG. 135.
[0365]
In FIG. 135, light from a lamp 1221a is converted into substantially parallel light (light with narrow directivity) by a parabolic mirror 1221b and emitted. The emitted light is cut off infrared rays and ultraviolet rays by the UVIR cut filter 1221c, and only visible light is emitted. Half of the light is reflected by a half mirror 1351 as indicated by a dotted line, and the light that has passed is reflected by a mirror 1352 as indicated by a solid line. Note that the half mirror 1351 and the mirror 1352 may be dichroic mirrors or dichroic prisms.
[0366]
A microlens array 1225 is attached to the liquid crystal display panel 1333 with an optical coupling agent, and one microlens 1225 corresponds to two pixels 244a and 244b. The light of the dotted line passes through the pixel 244a and the light of the solid line passes through the pixel 244b by the microlens 1225. This is light for the left eye and light for the right eye. With the above configuration, 3D display can be performed as in FIG.
[0367]
In the above 3D display system, one liquid crystal display panel 1333 alternately displays a left-eye image and a right-eye image for each pixel. However, in the above configuration, only one half of the number of pixels of the liquid crystal display panel can be seen when considering one eye. In other words, this is the same as looking at a display screen with half the number of pixels of the liquid crystal display panel.
[0368]
FIG. 129 shows a configuration of a 3D display system that solves this problem. It is not used in the image splitter 1231 or the like. The point that the principal rays of the two lamps 11 are inclined at an angle of θ with respect to the normal line of the liquid crystal display panel 1333, and that the light condensing means (lens 1252) converts the light emitted by the lamps 11 into light with narrow directivity. Is similar to FIG. That is, light mainly from the lamp 11a is light for the left eye, and light from the light emitting element 11b is light for the right eye. This is because the directivity of light emitted from the liquid crystal display panel 1333 is sufficiently small. As the liquid crystal display panel 1333, an active matrix type TN liquid crystal display panel is employed.
[0369]
FIG. 131 is a block diagram of a circuit for producing a video signal to be applied to the liquid crystal display panel 1333. The reproducing apparatus a and the reproducing apparatus b can output video signals in synchronization in a horizontal scanning period (H period). Synchronization is performed by a synchronization circuit 1311. The method and apparatus for achieving these synchronizations can be easily configured by those skilled in the video field, and thus description thereof is omitted. The video signals read from the playback devices a and b are subjected to analog-to-digital conversion by the A / D converter 1313, and are stored as data in memories 1314a and 1314b composed of SRAMs. The data is selectively read from the memories a and b by switching a switch of the switching circuit 1315. The read video data is digital-to-analog converted by the D / A converter 1316, and is added with a horizontal synchronizing signal or the like to become a video signal, which is applied to the terminal a of the switch SW1 in FIG.
[0370]
Reading from the memory a is performed in a half period (double speed reading) of one field (1F). In the remaining half period, 0 data (no video data = black display (no display)) is transferred to the D / A converter 1316. Similarly, reading from the memory b is performed in a half period of one field (1F), and 0 data (no video data = black display (no display)) is supplied to the D / A converter 1316 in the remaining half period. Will be transferred. That is, the video signal for the left eye is not displayed during the half period of the first field, and the video signal for the right eye is not displayed during the remaining half period of the second field. Are output from the D / A converter 1316 during which the half period is not displayed. It should be noted that the 期間 period is used for convenience of explanation and for ease of circuit configuration, and is not limited to this. For example, a video signal may be displayed during a 3/4 period, and no display may be performed during the remaining 1/4 period. Further, the present invention is not limited to one field, and may be one frame. For example, the video signal for the left eye may be displayed in a half period (= 2 fields) of one frame, and the remaining half period may not be displayed. However, when the interval at which the left-eye video signal is displayed becomes longer, flicker occurs, or the displayed image loses continuity and the moving image becomes awkward. In the case of a still image, the display interval of the video signal may be long, but in the case of a moving image display, this will be a problem. From this viewpoint, it is preferable that the appearance interval of the video signal for the left eye is one frame (= 2 fields).
[0371]
FIG. 130 illustrates the image display state of the liquid crystal display panel 1333, the lighting timing of the two light emitting elements 11a and 11b, and the signal polarity applied to the pixel electrode of the liquid crystal display panel 1333.
[0372]
First, the display state of the liquid crystal display panel 1333 will be described (the second column from the left in the drawing). (1) shows a non-display state (in the non-display state, the effective display area of the liquid crystal display panel is indicated by oblique lines). In addition, for ease of explanation, the video display uses the letter “F” as an example, and the display for the left eye is indicated by a solid line, and the display for the right eye is indicated by a dotted line. In (2), images are sequentially displayed from the top of the display screen, and (3) shows a state in which one entire screen is displayed. Next, in (4), the screen becomes a non-display state from above. (5) shows a state where no display (black display) is obtained. Note that steps (2) to (5) are performed continuously rather than quantumly. That is, in the liquid crystal display panel 1333, the gate drive circuit (not shown) applies the ON voltage of the TFT to the gate signal line every one horizontal scanning period (1H), and sequentially scans the gate signal line with the ON voltage. Do.
[0373]
In (2) to (5), an arbitrary pixel is displayed as an image for half a period of one field (1F). At this time, the left eye light emitting element 11a is turned on (ON), and the right eye light emitting element 11b is turned off (OFF). Therefore, an image for the left eye is displayed on the liquid crystal display panel 1333, and the optical image of the image display reaches the left eye of the observer by the light emitted from the light emitting element 11a. The black display (no display) is performed because the active matrix type liquid crystal display panel (or rather, the liquid crystal display panel) has a memory property. The memory property means that a signal written to the pixel electrode 244 is held until a signal is applied to the pixel electrode 244 next time. If black display is not performed, a state in which a display for the left eye and a display for the right eye are simultaneously displayed on the liquid crystal display panel 1333 occurs. If displayed simultaneously, even if the left-eye lamp 11a and the right-eye lamp 11b are alternately turned on and off, the image for the left eye reaches the right eye, and the image for the right eye reaches the left eye. No. As shown in FIG. 130, after displaying the image for the left eye, once the voltages held in all the pixel electrodes 244 are reset (erased) and a new image for the right eye is displayed, the image for the left eye is displayed. And the image for the right eye can selectively reach the left eye and the right eye, respectively.
[0374]
(6) to (9) indicate that an image for the right eye is displayed. At that time, the left-eye lamp 11a is turned off (off), and the right-eye lamp 11b is turned on (on). The image for the right eye is displayed on the liquid crystal display panel 1333 from the upper end of the screen. After the image for the right eye is completely displayed as shown in (7), the display is changed to black from the upper part as shown in (8). To go. The states (2) to (5) (image display state for the left eye) and the states (6) to (8) (image display state for the right eye) are repeated for each frame.
[0375]
The left eye lamp 11a is lit in the display state of (2), but is not limited to this, and may be lit as in the display state of (1). Similarly, the right eye lamp 11b may be turned on in the display state of (5).
[0376]
130 shows the polarity of the signal applied to the pixel electrode 244. The positive polarity with respect to the potential of the counter electrode 243 is indicated by “+”, and the negative polarity by “−”. A signal of the same polarity is applied to the row (horizontal direction) of one pixel electrode 244. Further, the polarity is inverted for each row. That is, in FIG. 130A, a signal having the same polarity is applied to the pixel electrodes 74a and 74b and a signal having the opposite polarity is applied to the pixel electrodes 244a and 244c.
[0377]
In the next field (FIG. 130 (b)), the signal polarity of each pixel electrode is set to be opposite to that of the previous field (FIG. 130 (a)). That is, the “−” polarity is applied to the pixel electrode 244c in FIG. 130A, but the “+” polarity is applied in FIG. 130B. As described above, by inverting the signal polarity applied to the pixel electrode 244 for each field, it is possible to prevent the occurrence of flicker and realize a good image display.
[0378]
FIG. 130 shows that the light emitted from the lamp 11a is incident on the left eye and the light emitted from the lamp 11b is incident on the right eye using the light condensing means (lens 1252). The same 3D display can be realized by using a lenticular lens 1271 as shown in FIG. 127 instead of the light collecting means. The image display state of the liquid crystal display panel 1333 and the light emission state of the light emitting elements (the lamps 11a and 11b) are the same as those shown in FIG. However, the lamps 11a and 11b need to be changed, but there is no fundamental problem.
[0379]
FIG. 128 is an explanatory diagram of an optical path and the like passing through a lenticular lens 1271 part. The lenticular lens 1271a is optically coupled (OC) to the array substrate 242 via the optical coupling agent 901a, and the lenticular lens 1271b is OC-coupled to the opposing substrate 241 via the optical coupling agent 901b. This is for preventing interface reflection and the like.
[0380]
Light (solid line) emitted from the lamp 11a enters the lenticular lens 1271a, passes through the pixel electrode 244 of the liquid crystal display panel 1333, is refracted by the lenticular lens 1271b, and enters the right eye. On the other hand, light (dotted line) emitted from the lamp 11b enters the lenticular lens 1271a, similarly passes through the pixel electrode 244 of the liquid crystal display panel 1333, and is refracted by the lenticular lens 1271b to enter the left eye.
[0381]
From the above, it can be understood that the light emitted from the lamps 11a and 11b can selectively reach the right and left eyes. That is, the lenticular lens 1271 has the same function as the condensing unit (lens 1252) in FIG. Therefore, if the display method of FIG. 130 is implemented, 3D display can be performed.
[0382]
The technical idea of providing two lamps can also be realized with the configuration shown in FIG. In the light shielding plate 1393 and the light shielding pattern 1392, two micro holes (1391a, 1391b) are formed for one micro lens 1225. The light emitted from the hole 1391a is converted to light for the right eye by the microlens 1225, and the light emitted from the hole 1391b is converted to light for the left eye by the microlens 1225. In this manner, one microlens array 1224 can produce light for the left eye and light for the right eye with good directivity. Further, the present invention can be realized not only with the micro lens array but also with the cell hook (cylindrical) lens array of FIG.
[0383]
In the 3D display of the reference example related to the present invention, since the lamp 11 which can be regarded as a point light source is used, the directivity of light emitted from the liquid crystal display panel 1333 is narrow. Therefore, light for the left eye and light for the right eye can be satisfactorily separated. In addition, by setting the angles of the principal rays emitted from the two lamps 11 to + θ and −θ, the observer can view the display image at the center of the screen of the liquid crystal display panel 1333 satisfactorily. Further, it is easy to change the angle of the chief ray. Further, it is easy to change the position of the lamp 11. For example, if the light emitting element (lamp 11) is moved to the position indicated by the dotted line in FIG. 33, the display image on the display panel 223 can be displayed in 3D when viewed from an oblique direction.
[0384]
In a 3D display system including two lamps, it is easy for an observer to adjust the 3D image to be optimally viewed. As shown in FIG. 132, the angle θ emitted from the lamp 11 may be adjusted. For example, as shown in FIG. 132A, when the observer's eyes 1401 are relatively separated from the display screen of the display panel 1333 (when the display screen is viewed from a relatively long distance), the angle θ is set.₁Smaller. On the other hand, as shown in FIG. 132B, when the observer's eye 1401 is relatively close to the display screen, the angle θ2 may be increased.
[0385]
More specifically, the configuration is as shown in FIG. A lamp 11 having a reflection mirror 833 is attached to arms 1412a and 1412b with screws 1411a and 1411b. One end of the arm 1412 is attached to an adjustment plate 1414 with screws 1411c. Further, an arm 1412 is attached to a hole of the slide plate 1413 by screws 1411a and 1411b.
[0386]
Pulling the adjustment plate 1414 rightward opens the space between the two lamps 11. Further, the distance between the lamps 11 is reduced by pushing the lamp. By adjusting the adjustment plate 1414 by the observer as described above, it is easy to optimally view the 3D display.
[0387]
The viewfinder described above converts light radiated from a small luminous body of a light emitting element at a wide solid angle into near parallel light with a Fresnel lens or parabolic mirror or the like, and modulates the light with a liquid crystal display panel 1333. Since the image is displayed on the screen, the power consumption is small and the brightness unevenness is small. In addition, since the driving circuit of the lamp 11 has a simple configuration as compared with a conventional viewfinder using a backlight, a compact and lightweight viewfinder can be provided. When a PD liquid crystal display panel is used as a liquid crystal display panel, power consumption can be further reduced as compared with a TN liquid crystal display panel. Further, by disposing the diffusion plate 15 between the Fresnel lens 522 and the like and the liquid crystal display panel 1333, it is possible to prevent the pixel 244 of the liquid crystal display panel 1333 from interfering with the groove of the Fresnel lens 522 to generate moire. It is possible to suppress the visual recognition of the groove, so that a good image display can be realized. In addition, by making the diffusion plate 15 a PD liquid crystal display panel, it is possible to adjust the viewing angle and the brightness (brightness, brightness, etc.) of the displayed image. In addition, since a lamp that can be regarded as a point light source can be used as the lamp 11, good 3D display can also be realized.
[0388]
【The invention's effect】
A low power consumption liquid crystal display device and a viewfinder using the same can be provided.
[Brief description of the drawings]
FIG. 1 is a sectional view of a viewfinder according to a reference example relating to the present invention.
FIG. 2 is a cross-sectional view of a light source unit of a viewfinder according to a reference example related to the present invention.
FIG. 3 is a sectional view of a light source unit of a viewfinder according to a reference example relating to the present invention.
FIG. 4 is a sectional view of a light source unit of a viewfinder according to a reference example relating to the present invention.
FIG. 5 is an explanatory diagram of a viewfinder of a reference example related to the present invention.
FIG. 6 is a sectional view of a light source unit of a viewfinder according to a reference example relating to the present invention.
FIG. 7 is an explanatory diagram of a light source unit of a viewfinder according to a reference example related to the present invention.
FIG. 8 is a cross-sectional view of a light source unit of a viewfinder according to a reference example relating to the present invention.
FIG. 9 is an explanatory diagram of a lamp of a viewfinder of a reference example related to the present invention.
FIG. 10 is an explanatory view of a lamp of a viewfinder according to a reference example relating to the present invention.
FIG. 11 is an explanatory diagram of a lamp of a viewfinder of a reference example related to the present invention.
FIG. 12 is an explanatory diagram of a lamp of a viewfinder of a reference example related to the present invention.
FIG. 13 is an explanatory diagram of a lamp of a viewfinder of a reference example related to the present invention.
FIG. 14 is an explanatory diagram of a lamp of a viewfinder of a reference example related to the present invention.
FIG. 15 is an explanatory diagram of a viewfinder according to a reference example related to the present invention.
FIG. 16 is an explanatory diagram of a lamp driving method according to a reference example relating to the present invention.
FIG. 17 is an explanatory diagram of a lamp driving method according to a reference example relating to the present invention.
FIG. 18 is an explanatory diagram of a lamp driving method according to a reference example relating to the present invention.
FIG. 19 is an explanatory diagram of a lamp driving method according to a reference example relating to the present invention.
FIG. 20 is an explanatory diagram of a lamp driving method according to a reference example relating to the present invention.
FIG. 21 is an explanatory diagram of a viewfinder of a reference example related to the present invention.
FIG. 22 is an explanatory diagram of a viewfinder of a reference example related to the present invention.
FIG. 23 is a sectional view of a polymer dispersed liquid crystal display panel.
FIG. 24 is an explanatory diagram of a polymer dispersed liquid crystal display panel.
FIG. 25 is a sectional view of a light source section of a viewfinder according to a reference example relating to the present invention.
FIG. 26 is a sectional view of a light source unit of a viewfinder according to a reference example relating to the present invention.
FIG. 27 is a cross-sectional view of a viewfinder of a reference example related to the present invention.
FIG. 28 is an explanatory diagram of a lamp of a viewfinder of a reference example related to the present invention.
FIG. 29 is a sectional view of a lamp of a viewfinder of a reference example related to the present invention.
FIG. 30 is a sectional view of a lamp of a viewfinder according to a reference example relating to the present invention.
FIG. 31 is an explanatory diagram of a lamp of a viewfinder according to a reference example relating to the present invention.
FIG. 32 is an explanatory diagram of a light source unit of a viewfinder of a reference example related to the present invention.
FIG. 33 is an explanatory diagram of a light source unit of a viewfinder of a reference example related to the present invention.
FIG. 34 is an explanatory diagram of a light source unit of the viewfinder according to the present embodiment.
FIG. 35 is an explanatory diagram of a light source unit of a viewfinder of a reference example related to the present invention.
FIG. 36 is an explanatory diagram of a light source unit of a viewfinder of a reference example related to the present invention.
FIG. 37 is an explanatory diagram of a lamp of a viewfinder of a reference example related to the present invention.
FIG. 38 is a perspective view of a light source unit of a viewfinder of a reference example related to the present invention.
FIG. 39 is a perspective view of a light source unit of a viewfinder of a reference example related to the present invention.
FIG. 40 is a perspective view of a light source unit of a viewfinder of a reference example related to the present invention.
FIG. 41 is a perspective view of a light source unit of a viewfinder of a reference example related to the present invention.
FIG. 42 is an explanatory diagram of a lamp driving method according to a reference example relating to the present invention.
FIG. 43 is an explanatory diagram of a video camera of a reference example related to the present invention.
FIG. 44 is an explanatory diagram of a video camera of a reference example related to the present invention.
FIG. 45 is an explanatory diagram of a lamp driving method according to a reference example relating to the present invention.
FIG. 46 is an explanatory diagram of a lamp driving method according to a reference example relating to the present invention.
FIG. 47 is an explanatory diagram of a lamp of a viewfinder according to a reference example relating to the present invention.
FIG. 48 is an explanatory diagram of a light source unit of a viewfinder of a reference example related to the present invention.
FIG. 49 is an explanatory diagram of a method of driving a lamp of a viewfinder according to a reference example relating to the present invention.
FIG. 50 is an explanatory diagram of an LED.
FIG. 51 is an explanatory diagram of an LED.
FIG. 52 is an explanatory diagram of a phosphor screen light emitting device.
FIG. 53 is an explanatory diagram of a video camera of a reference example related to the present invention.
FIG. 54 is an explanatory diagram of an electronic still camera of a reference example related to the present invention.
FIG. 55 is a sectional view of a viewfinder according to a reference example relating to the present invention;
FIG. 56 is a sectional view of a viewfinder according to a reference example relating to the present invention;
FIG. 57 is an explanatory diagram of a viewfinder according to a reference example relating to the present invention;
FIG. 58 is an explanatory diagram of a viewfinder according to a reference example relating to the present invention;
FIG. 59 is an explanatory diagram of a viewfinder of a reference example related to the present invention.
FIG. 60 is an explanatory diagram of a viewfinder of a reference example related to the present invention.
FIG. 61 is an explanatory diagram of a viewfinder according to a reference example relating to the present invention.
FIG. 62 is an explanatory diagram of a display device of a reference example related to the present invention.
FIG. 63 is an explanatory diagram of a display device of a reference example related to the present invention.
FIG. 64 is an explanatory diagram of a viewfinder of a reference example related to the present invention.
FIG. 65 is an explanatory diagram of a viewfinder of a reference example related to the present invention.
FIG. 66 is an explanatory diagram of a viewfinder of a reference example related to the present invention.
FIG. 67 is an explanatory diagram of a viewfinder of a reference example related to the present invention.
FIG. 68 is an explanatory diagram of a viewfinder of a reference example related to the present invention.
FIG. 69 is an explanatory diagram of a viewfinder according to a reference example relating to the present invention.
FIG. 70 is an explanatory diagram of a viewfinder according to a reference example relating to the present invention;
FIG. 71 is an explanatory diagram of a viewfinder of a reference example related to the present invention.
FIG. 72 is an explanatory diagram of a viewfinder of a reference example related to the present invention.
FIG. 73 is an explanatory diagram of a viewfinder according to a reference example relating to the present invention;
FIG. 74 is an explanatory diagram of a viewfinder of a reference example related to the present invention.
FIG. 75 is an explanatory diagram of a viewfinder of a reference example related to the present invention.
FIG. 76 is an explanatory diagram of a viewfinder of a reference example related to the present invention.
FIG. 77 is an explanatory diagram of a viewfinder of a reference example related to the present invention.
FIG. 78 is an explanatory diagram of a viewfinder according to a reference example relating to the present invention;
FIG. 79 is an explanatory diagram of a viewfinder according to a reference example relating to the present invention;
FIG. 80 is an explanatory diagram of a viewfinder according to a reference example relating to the present invention;
FIG. 81 is an explanatory diagram of a viewfinder according to a reference example relating to the present invention;
FIG. 82 is a perspective view of a viewfinder according to a reference example relating to the present invention;
FIG. 83 is a sectional view of a viewfinder according to a reference example relating to the present invention;
FIG. 84 is a cross-sectional view of a viewfinder of a reference example related to the present invention.
FIG. 85 is an explanatory diagram of a video camera of a reference example related to the present invention.
FIG. 86 is an explanatory diagram of a viewfinder according to a reference example relating to the present invention;
FIG. 87 is an explanatory diagram of a viewfinder according to a reference example relating to the present invention;
FIG. 88 is an explanatory diagram of a viewfinder of a reference example related to the present invention.
FIG. 89 is an explanatory diagram of a light source unit of a viewfinder of a reference example related to the present invention.
FIG. 90 is an explanatory diagram of a light source unit of a viewfinder of a reference example related to the present invention.
FIG. 91 is an explanatory diagram of a light source unit of a viewfinder of a reference example related to the present invention.
FIG. 92 is an explanatory diagram of a viewfinder according to a reference example relating to the present invention;
FIG. 93 is an explanatory diagram of a viewfinder of a reference example related to the present invention.
FIG. 94 is an explanatory diagram of a viewfinder of a reference example related to the present invention.
FIG. 95 is a sectional view of a viewfinder according to a reference example relating to the present invention;
FIG. 96 is an explanatory diagram of a viewfinder according to a reference example relating to the present invention;
FIG. 97 is an explanatory diagram of a display panel of a reference example related to the present invention.
FIG. 98 is an explanatory diagram of a viewfinder according to a reference example relating to the present invention;
FIG. 99 is a sectional view of a viewfinder according to a reference example relating to the present invention;
FIG. 100 is a sectional view of a viewfinder according to a reference example relating to the present invention;
FIG. 101 is an explanatory diagram of a viewfinder according to a reference example relating to the present invention;
FIG. 102 is an explanatory diagram of a viewfinder according to a reference example relating to the present invention;
FIG. 103 is an explanatory diagram of a viewfinder according to a reference example relating to the present invention;
FIG. 104 is an explanatory diagram of a viewfinder according to a reference example relating to the present invention;
FIG. 105 is an explanatory diagram of a viewfinder according to a reference example relating to the present invention;
FIG. 106 is an explanatory diagram of a viewfinder according to a reference example relating to the present invention;
FIG. 107 is a sectional view of a viewfinder according to a reference example relating to the present invention;
FIG. 108 is a sectional view of a viewfinder according to a reference example relating to the present invention;
FIG. 109 is a cross-sectional view of a viewfinder of a reference example related to the present invention.
FIG. 110 is a sectional view of a viewfinder according to a reference example relating to the present invention;
FIG. 111 is a sectional view of a viewfinder according to a reference example relating to the present invention;
FIG. 112 is an explanatory diagram of a viewfinder according to a reference example relating to the present invention;
FIG. 113 is an explanatory diagram of a viewfinder according to a reference example relating to the present invention;
FIG. 114 is an explanatory diagram of a viewfinder according to a reference example relating to the present invention;
FIG. 115 is an explanatory diagram of a viewfinder according to a reference example relating to the present invention;
FIG. 116 is a cross-sectional view of a viewfinder of a reference example related to the present invention.
FIG. 117 is a perspective view of a viewfinder of a reference example related to the present invention.
FIG. 118 is a sectional view of a viewfinder according to a reference example relating to the present invention;
FIG. 119 is a cross-sectional view of a viewfinder of a reference example related to the present invention.
FIG. 120 is an explanatory diagram of a viewfinder of a reference example related to the present invention.
FIG. 121 is an explanatory diagram of a viewfinder of a reference example related to the present invention.
FIG. 122 is a configuration diagram of a display device of a reference example related to the present invention.
FIG. 123 is an explanatory diagram of a display device of this embodiment.
FIG. 124 is an explanatory diagram of a display device in this embodiment.
FIG. 125 is an explanatory diagram of a display device of this embodiment.
FIG. 126 is an explanatory diagram of a lens used for a display device in this embodiment.
FIG. 127 is an explanatory diagram of a display device of this embodiment.
FIG. 128 is an explanatory diagram of a display device of this embodiment.
FIG. 129 is an explanatory diagram of a display device of a reference example related to the present invention.
FIG. 130 is an explanatory diagram of a display device of this embodiment.
FIG. 131 is an explanatory diagram of a driving method of a display device of a reference example related to the present invention.
FIG. 132 is an explanatory diagram of a driving method of a display device of a reference example related to the present invention.
FIG. 133 is an explanatory diagram of a display device of a reference example related to the present invention.
FIG. 134 is an explanatory diagram of a display device of a reference example related to the present invention.
FIG. 135 is a configuration diagram of a display device of a reference example related to the present invention.
FIG. 136 is an external view of a viewfinder.
FIG. 137 is a cross-sectional view of a conventional viewfinder.
FIG. 138 is an explanatory diagram of a light source unit of a conventional viewfinder.
FIG. 139 is an explanatory diagram of a viewfinder according to a reference example relating to the present invention;
FIG. 140 is a design example of a viewfinder according to a reference example relating to the present invention;
FIG. 141 is a design example of a viewfinder of a reference example related to the present invention.
FIG. 142 is a design example of a viewfinder according to a reference example relating to the present invention;
FIG. 143 is a design example of a viewfinder according to a reference example related to the present invention;
FIG. 144 is a design example of a parabolic mirror of a viewfinder of a reference example related to the present invention.
[Explanation of symbols]
11 lamp
12 Parabolic mirror
14 Base board
15 Diffusion (scattering) sheet
16 Lamp potential terminal
16a, b filament terminals
16c anode terminal
17 Lamp circuit components
20 Sealing member
21, 21a Lamp case
22 Reflective surface
23 phosphor
24 filament
25 Anode electrode
26 cushioning member
27 socket
28 terminals
29 Solder
30, 30a protrusion
31 Reflective film
32 light reflection tube
15a Diffusion plate
43 Embossed surface
51 rays
52 Effective display area
71 Low brightness area
72 Rubber cap
73 Projection
91 Reflective film
101 Light collection cap
102 condenser prism
103 adhesive
104 transparent resin
105 reflective tube
106 Diffuser
107 Reflective cap
111 Transparent conductive film (ITO)
112 Antistatic film
121 conductor
131 Wire mesh
161 timer circuit
162 Variable power supply
163 Variable resistor (variable current element)
171 Inverter
172a, b Analog switch
173a, b Current limiting resistor
181 Photo sensor
182 operational amplifier
183 light detection circuit
184 oscillation circuit
185 amplifier
191 amplifier
192 Phase division circuit
193 output switching circuit
194 drive circuit control unit
195 source drive circuit
196 Gate drive circuit
197,198 power supply
201a, b DCDC converter
202 Battery
204 Current detection circuit
211 Outside
212 Aperture knob
213 Iris diaphragm
249 source signal line
230 color filter
231 Transparent resin
241 Counter electrode substrate
242 array board
243 Counter electrode
244 pixel electrode
245 Droplet liquid crystal
246 polymer
247 Incident light
248 Light modulation layer (liquid crystal layer)
291 protective film (SiO₂)
301 mounting glass
311 Light emitting area
312 marker
313 hollow
314 Transparent protrusion
331 Diffusion (scattering) part
332 Diffusion (scattering) point
381 Transparent holder (resin resin)
382 Holder fixing part
391 Parabolic mirror
401 convex
411 Diffusing (scattering) plate
421 Thermistor
422 comparator
423 CPU
424 switch circuit
425 operational amplifier
426 FET
431 video camera body
432 Imaging lens unit
433 switch (SW)
434 connection
435 Recording switch
471 Sealing resin
501 terminal
502 luminous body
503 resin lens
504 lens surface
505 Top of lens surface
506 lens surface normal
507 Center of curvature of lens surface
508 Image of luminous body by lens surface
521 fluorescent lamp
531 CCD sensor
532 Light emitting element power supply circuit
533 Liquid crystal display panel drive circuit
534 playback circuit
541 still camera body
551 reflector
552 Illumination lens (convex lens)
553 auxiliary lens
601 lens surface
602 Fresnel surface
603 convex lens
604 Fresnel lens
611 flat part
621 Light guide plate
622 diffusion unit
631 prism plate
641 Eye Point
681 Panel holder
691 display
711 socket
712 knob
713 Contraction part 1
714 Contraction part 2
715 Optical axis
751 mirror
811 Insertion part
821 Knob
831 Reflector
1336b concave lens
851 Fastener
861 Panel mounting part
862 Bellows
863 Rotation axis
864 lens mount
871 case
872 rays
881 cylindrical lens
882 small fluorescent tube
883 Reflector
901 Transparent adhesive
911 elliptical mirror
912 shading plate
921 diffusion unit
931 circular aperture
932 diffraction grating
951 Photosynthetic surface
952 PBS
953 dichroic mirror
961 optical axis
971 display area
972 push button
973 telephone body
974 handset
975 Infrared LED
976 light receiving element
991 Mounting holder
1011 Transparent substrate
1012 Light absorbing film
1022, 1023, 1024, 1031 interface
1031 interface
1041 PD liquid crystal display panel
1042 signal source
1043 Signal amplitude changer
1044 sealing resin
1045 Glass substrate
1046 ITO electrode
1047 PD liquid crystal layer
1051 Optical coupling layer
1091 aperture
1111 Light guide
1121 Reflective film
1131 Optical fiber
1141 Sunlight
1142 Photo sensor
1143 Fresnel lens
1151 hysteresis comparator circuit
1152 Light detection circuit
1153 Switch circuit
1171 Shading cover
1211 Reflective Fresnel lens
1221 light source
1221a Metal halide lamp
1221b concave mirror
1221c UVIR cut mirror
1222 Projection lens
1223 color filter
1224 micro lens array
1225 micro lens
1231 Image splitter
1232 chief ray
1241 opening
1242 shading part
1243 Left eye image
1244 Right eye image
1245 Observer
1251 Boost coil
1252 condenser lens (convex lens)
1261 Cell Hook Lens
1271 Lenticular lens
1311 Synchronous circuit
1312 playback device
1313 A / D conversion circuit
1314 frame memory
1315 Switching circuit
1216 D / A conversion circuit
1401a Right eye
1401b left eye
1411 screw
1412 arm
1413 slide plate
1414 Adjustment plate
1341 prism plate
1351 half mirror
1352 mirror
1321 Body
1323 Mounting bracket
1331 fluorescent tube box
1332 Eyepiece cover
1333 LCD panel
1334 Polarizing plate
1335 Mounting holder
1336 magnifying lens
1341 Light emission pattern of fluorescent tube

Claims (5)

A liquid crystal display panel,
Lighting means having a left-eye light-emitting element and a right-eye light-emitting element for illuminating the liquid crystal display panel,
Signal processing means for displaying an image for the left eye and an image for the right eye on the liquid crystal display panel,
Lighting control means for controlling on and off of the light emitting element for the left eye and the light emitting element for the right eye of the lighting means,
The signal processing means, on the liquid crystal display panel, sequentially displays the image for the left eye from one end of the screen, after displaying the image for the left eye, the image for the left eye from one end of the screen Delete or display a black image,
The signal processing means, on the liquid crystal display panel, sequentially display the image for the right eye from one end of the screen, after displaying the image for the right eye, the image for the right eye from one end of the screen Delete or display a black image,
The lighting control means turns on and off the light emitting element for the left eye in synchronization with the display of the image for the left eye,
The lighting control means turns on and off the light emitting element for the right eye in synchronization with the display of the image for the right eye ,
The distance between the light emitting element for the left eye and the light emitting element for the right eye varies according to the distance between the liquid crystal display panel and the observer in the direction of incidence of the principal ray illuminating the liquid crystal display panel. a liquid crystal display device comprising an adjustable der Rukoto as. Before SL signal processing means, a liquid crystal display device according to claim 1, wherein the polarity for each pixel row to the liquid crystal display device Ru is held a different signal. Before Symbol illumination control means, a liquid crystal display device according to claim 1, wherein the can vary the direction of incidence of the principal ray that illuminates the liquid crystal display panel. The left-eye light emitting element and the right-eye light emitting element, the liquid crystal display device according to any one of claims 1 to 3, characterized in that to generate white light by the action of the phosphor. A liquid crystal display device according to any one of claims 1 to 3 ,
A viewfinder, comprising: a magnifying lens that magnifies a display image of the liquid crystal display device so as to be seen by an observer.

Images